P-1 (General) SHIVAJI UNIVERSITY, KOLHAPUR Schedule/Practical Exam 2015... · P-3 SHIVAJI...

P-1 (General)

SHIVAJI UNIVERSITY, KOLHAPUR

B. Sc. Part-III / Chemistry Practical Examination, February/March, 2015

(PHYSICAL)

1. Write your examination seat number and table number on the answer book.

2. Show your observations and weights etc. to the examiner and get them initialled.

3. Show all details of all calculations to deserve full credit for calculations.

4. Detail calculation means use of formulae, substitution and calculations by Scientific

calculator / log table.

5. Draw Circuit diagram wherever necessary.

6. Do not make any calculations on scraps of papers.

7. S. I. Units Should be followed as far as possible.

P-2



Time : 31/4 hours Marks - 25

To determine partition coefficient of acetic acid between water and carbon tetrachloride.

Given : 2N acetic acid, 1N acetic acid, 0.5N acetic acid, 0.5N NaOH, 0.01N NaOH, pure CCl4.

Apparatus : Reagent bottles, burette, 10cm3 pipette etc.

Procedure : (1) Prepare following three mixtures in three separate bottles numbered as 1, 2 and 3

Bottle No. Volume of acetic acid Volume of CCl4

1 50 cm3 2 N acetic acid 50 cm3

2 50 cm3 1 N acetic acid 50 cm3

3 50 cm3 0.5 N acetic acid 50 cm3

(2) Keep these bottles in water bath at room temperature and shake all the

mixtures vigorously from time to time, for about 20 minutes

(3) Titration of CCl4 Layer (Lower) :

From each bottle, pipette out 10cm3 of CCl4 layer (lower), add 50cm3 distilled

water and titrate it with 0.01N NaOH using phenolphthalein as an indicator.

End point is colourless to pink.

(4) Titration of an Aqueous Layer (Upper) :

From each bottle, pipette out 10cm3 of an aqueous layer (upper) and titrate it

with 0.5N NaOH using phenolphthalein as an indicator. End point is

colourless to pink.

(5) Enter the results in a tabular form as follows :

Observation Table

Calculations :

(a) Calculate normalities of CCl4 and aqueous layers.

(b) Calculate concentrations of CCl4 [CCCl

4] and aqueous [Caq] layers.

(c) Determine partition coefficient (K) using the equation, K =

Results :

(i) Mean partition coefficient = .................

(ii) Conclusion

Bottle

No.

1

2

3

Titration

Reading for

CCl4 layer

cm3

Titration

Reading for

Aqueous layer

cm3

Normality

of

CCl4 layer

Normality

of

aqueous

layer

Conc. of

CCl4 layer

mol dm–3

CCCl4

Conc. of

Aq. layer

mol dm–3

Caq

K =

CCCl

4

Caq

√

CCCl

4

Caq

√

P-3




To determine the energy of activation of a reaction of hydrolysis of methyl acetate in

presence of 0.5N acid (HCl/H2SO

4).

Given : 0.5N HCl/H2SO

4, 0.1N NaOH, methyl acetate etc.

Apparatus : Water bath, thermostat, burette, 5cm3 pipette etc.

Procedure : Perform the experiment in two sets as follows :

Set I : At lower or Room Temperature (T1 K) :

(1) Take the following solutions in two separate bottles

Bottle No. 1 : 5 cm3 methyl acetate

Bottle No. 2 : 100 cm3 0.5N HCl/H2SO

4

Keep these bottles in water bath at room temperature for about 10 min.

(2) Add acid solution from bottle No. 2 to methyl acetate in bottle No. 1, note the

time of mixing as zero time shake the mixture well. Immediately pipette out

5cm3 of the reaction mixture in conical flask containing ice and titrate it with

0.1N NaOH using phenolphthalein as an indicator. End point is colourless to

pink. Measure burette reading. This is zero time reading (T0)

(3) In this way, titrate 5ml of the reaction mixture after every 10 minutes from

start of the reaction.

(4) Record the results in the Observation Table - 1

(5) Ask for T∞ reading

Observation Table 1

Set I Temp. (T1) = ..... K

a = (T∞ - T0) = ........ cm3

T∞ = ........ cm3

Time

min

Titration

Reading

Tt cm3

log —k

1

min–1

a

a-xx a-x a

a-x

0

10

20

30

40

50

Observation Table 2

Set II Temp. (T2) = ..... K

a = (T∞ - T0) = ........ cm3

T∞ = ........ cm3

Time

min

Titration

Reading

Tt cm3

log —k

2

min–1

a

a-xx a-x a

a-x

0

10

20

30

40

50

where x = (Tt – T

0) (P. T. O.)

(2)

Set II : At Higher Temperature (T2 K) :

(1) Repeating the same procedure as described for set I, carry out the experiment at

higher temperature T2 K (i.e. 100 higher than T

1) using thermostat.

(2) Record the results in observation Table 2.

Calculations :

(a) Calculate k1 and k

2 for each set using the equation,

k = ——— log ——

OR

(a) Plot a graph of log —— against time (t) for each set and find k1 and k

2 from the

slopes. Use the formula, k = 2.303 X slope

(b) Determine the energy of activation (Ea) using the equation,

log —— = ———— [ — – — ]

(R = 8.314 J K–1 mol–1 )

Results :

(i) k1 = ................. min–1

(ii) k2 = ................. min–1

(iii) Ea = ................. kJ

2.303

t

a

a-x

a

a-x

k2

k1

Ea

2.303 R

1

T1

1

T2

P-3

2.303 R T1 T

2

(T2 _

T1 )

logk

2

k1

Ea =

P-4




To determine the energy of activation of a reaction between potassium persulphate and

potassium iodide (Equal concentration).

Given : 0.1N K2S

2O

8, 0.1N KI, 0.002N Na

2S

2O

3, Starch solution etc.

Apparatus : Water bath, thermostat, burette, 10 cm3 pipette etc.


Set I : At lower or Room Temperature (T1 K) :


Bottle No. 1 : 20cm3 0.1N K2S

2O

8 + 20cm3 distilled water

Bottle No. 2 : 20cm3 0.1N KI + 20cm3 distilled water

Keep the bottles in water bath at room temperature for about 10 min.

(2) Add solution from bottle No. 2 to a solution in bottle No. 1, note the time of

mixing shake the mixture well and keep the bottle in water bath.

(3) After 10 min, pipette out 10cm3 of the reaction mixture in a conical flask

containing ice and titrate it with 0.002N Na2S

2O

3 solution using starch as an

indicator. End point is blue to colourless.

(4) In this way, titrate each time 10cm3 of the reaction mixture at the intervals of

15, 20, 25, 30 and 35 min. from the start of the reaction.

(5) Record the results in Observation Table 1.

Observation Table 1

Set I T1 = ..... K

a = ........................ cm3

Time

in min.

t

Titration

Reading

x cm3

10

15

20

25

30

35

(a-x)1

(a-x)

k1

dm3.

mol-1.min-1

Observation Table 2

Set II T2 = ..... K

a = ........................ cm3

Time

in min.

t

Titration

Reading

x cm3

10

15

20

25

30

35

(a-x)1

(a-x)

k2

dm3.

mol-1.min-1

(P. T. O.)

(2)



higher temperature (i.e. 100 higher than T1) using thermostat.


Calculations :

(a) Calculate initial concentration of K2S

2O

8 and KI.

(b) Calculate k1 and k

2 for each set using the equation,

k = — [ —— – — ]OR

(b) Plot a graph of —— against time (t) for each set and find k1 and k

2 from the slopes.

k = slope

(c) Determine the energy of activation (Ea) using the equation,

log —— = ———— [ — – — ]

(R = 8.314 J K–1 mol–1 )

Results :

(i) k1 = ................. dm3.mol-1.min-1

(ii) k2 = ................. dm3.mol-1.min-1

(iii) Ea = ................. kJ

k2

k1

Ea

2.303xR

1

T1

1

T2

1

t

1

a–x

1

a-x

1

a

P-4

k = — 1 x

t a(a-x)

2.303 R T1 T

2

(T2 _

T1 )

logk

2

k1

Ea =

P-5




To determine the energy of activation of the reaction between potassium persulphate and

potassium iodide (Unequal concentration)

Given : 0.1N K2S

2O

8, 0.1N KI, 0.002N Na

2S

2O

3, starch solution etc.

Apparatus : Water bath, thermostat, burette, 10cm3 pipette etc.


Set I : At Lower or Room Temperature (T1 K) :


Bottle No. 1 : 10 cm3 0.1 N K2S

2O

8 + 30 cm3 distilled water

Bottle No. 2 : 20 cm3 0.1 N KI + 20 cm3 distilled water



mixing shake the reaction mixture well and keep the bottle in water bath.

(3) After 10 min, pipette out 10 cm3 of the reaction mixture in conical flask

containing ice and titrate it with 0.002 N Na2S

2O



(4) In this way, titrate each time 10 cm3 of reaction mixture at the intervals of 15,

20, 25, 30 and 35 min. from the start of the reaction.


Observation Table 1

Set I T1 = .......... K

a = ............. cm3. b = .............. cm3.

Time

in min.

t

Titration

Reading

x cm3.

(a–x) (b–x)

10

15

20

25

30

35

log (–—)a–x

b–xa–x

b–x

Observation Table 2

Set II T2 = .......... K

a = ............. cm3. b = .............. cm3.

Time

in min.

t

Titration

Reading

x cm3.

(a–x) (b–x)

10

15

20

25

30

35

log (–—)a–x

b–x (–—)a–x

b–x

(P. T. O.)

(–—) k1

k2

dm3 mol min-1 -1

(2)



higher temperature (i.e. 100 higher than T1 ) using thermostat.


Calculations :


2O

8 and KI.

(b) Plot a graph of log ( ——) against time (t) for each set. From the graph find k1 and

k2 using the relation,

k = ——————

OR


2 for each set using the equation

(c) Calculate the energy of activation (Ea) using the equation.

log —— = ———— [ — – — ]

(R = 8.314 J K–1 mol–1 )

Results :

(i) k1 = ................. dm3.mol-1.min-1

(ii) k2 = ................. dm3.mol-1.min-1

(iii) Ea = ................. kJ

a-x

b-x

2.303 slope

(a - b)

P-5

k2

k1

Ea

2.303R

1

T1

1

T2

2.303

t (a-b) logb (a-x)

a (b-x)k =

2.303 R T1 T

2

(T2 _

T1 )

logk

2

k1

Ea =

P-6




To study the hydrolysis of methyl acetate by using its two concentrations in presence of

0.5 N HCl and hence find velocity constant of the reaction.

Given : 0.5N HCl, 0.1 N NaOH, methyl acetate etc.

Apparatus : Water bath, burette; 5cm3 pipette etc.

Procedure : Perform the experiment in two sets at room temperatureas follows :

Set I : By using 5 cm3 of methyl acetate:



Bottle No. 2 : 100 cm3 0.5 N HCl

Keep these bottles in water bath at room temperature for about 10 minutes

(2) Add acid solution from bottle No. 2 to methyl acetate in bottle No. 1, start the

stop watch, stir the mixture well, Immediately pipette out 5ml of the reaction

mixture in conical flask containing ice and titrate it with 0.1N NaOH using

phenolphthalein as an indicator. End point is colourless to pink. Note burette

reading. This is zero time reading (T0)

(3) In this way titrate 5 cm3 of the reaction mixture after every 10 minutes from

start of the reaction.


(5) Ask for T∞ reading

Observation Table 1

Set I Temp. (T1) = ........... K

a = (T∞ - T0) = ........... cm3

T∞ = ........... cm3

Time

min.

Titration

Reading

Tt ml.

x a-x

0

10

20

30

40

50

(P. T. O.)

Observation Table 2

Set II Temp. (T1) = ........... K

a = (T∞ - T0) = ........... cm3

T∞ = ........... cm3

a

a-xlog

a

a-x

k1

min-1

Time

min.

Titration

Reading

Tt cm3

x a-x

0

10

20

30

40

50

a

a-xlog

a

a-x

k2

min-1

where x = Tt - T

0

(2)

Set II : By using 10 cm3 of methyl acetate :

1) Take the following solutions in two separate bottles


Bottle No. 2 : 100 cm3 0.5N HCl

2) Keep these bottles in water bath at room temperature for about 10 min. Repeat the same

procedure as described for set I.

3) Ask for T∞ reading

4) Record the results in observation Table 2.

Calculations :

(a) Calculate k1 and k

2, for each set using the equation,

k = _____ log ___

OR

(a) Plot a graph of log ___ against-time (t) for each set and find k1 and k

2 from the slopes.

Use the formula, k = 2.303 x slope

Results :

(i) k1 = ........................ min-1.

(ii) k2 = ........................ min-1.

(iii) Conclusion :

P-6

2.303

t

a

a-x

a

a-x

P-7




To study the effect of addition of electrolyte (KCl) on the rate of reaction between potassium

persulphate and potassium iodide (Equal concentration).

Given : 0.1N K2S

2O

8, 0.1N KI, 0.4 M KCl, 0.002N Na

2S

2O

3, starch solution etc.

Apparatus : Water bath, burette, 10cm3 pipette etc.


Set I :



2O


Bottle No. 2 : 20 cm3 0.1 N KI + 20 cm3 distilled water



mixing shake the reaction mixture well and keep the bottle in water bath.

(3) After 10 min, pipette out 10 cm3 of the reaction mixture in conical flask

containing ice and titrate it with 0.002 N Na2S

2O



(4) In this way, titrate each time 10 cm3 of reaction mixture at the intervals of 15,

20, 25, 30 and 35 min. from the start of the reaction.


Observation Table 1

Set I a = ............. cm3.

Time

in

min. t

Titration

Reading

x cm3

(a–x) 1

(a–x)

10

15

20

25

30

35

Observation Table 2

Set II a = ............. cm3.

Time

in min.

t

Titration

Reading

x cm3

(a–x)

10

15

20

25

30

35

(P. T. O.)

k1

dm3 mol-1 min-1

1

(a–x)

k2

dm3 mol-1 min-1

(2)

Set II : By adding 0.4 M KCl solution.



2O


Bottle No. 2 : 20 cm3 0.1 N KI + 20 cm3 0.4 M KCl solution.


(2) Repeat the procedure as described for set 1.


Calculations :


2O

8 and KI.


2 using the relation,

k = __ [ ____ – __ ]

OR

(b) Plot a graph of ___ against time (t) for each set and find k1 and k

2 from the slopes

k = slope.

Results :

(i) k1 = ................. dm3.mol-1.min-1

(ii) k2 = ................. dm3.mol-1.min-1

(iii) Conclusion : ...................

P-7

1

t

1

(a-x)

1

a

1

(a-x)

k =1 x

t a.(a-x)

P-8




To determine the partial molar volume of ethyl alcohol in a mixture of ethyl alcohol and water.

Given : Ethyl alcohol and water.

Apparatus : Specific gravity bottle.

Procedure : 1) Prepare the mixtures of ethyl alcohol (A) and water (B) in separate stoppered

bottles. Choose any seven compositions from the following.

Bottle No. 1 2 3 4 5 6 7 8 9

Volume of ethyl alcohol (VA) 2 4 6 8 10 12 14 16 18

Volume of water (VB) 18 16 14 12 10 8 6 4 2

2) Assuming the density of water as dB = 1 gm/cm3, determine the densities of

all liquids by using specific gravity bottle

Density of liquid = _______________

Calculations :

(1) Calculate the weight of ethyl alcohol and weight of water in each mixture using the

relation,

Weight of ethyl alcohol = Vol. of ethyl alcohol x Density of ethyl alcohol and

Weight of Water = Vol. of water x Density of water

(2) Calculate the Moles of ethyl alcohol and Moles of water in each mixture using the

relation,

No. of moles = Weight / Mol. Wt.

Where, Mol. Wt. of water in 18 and Mol. Wt. of ethyl alcohol is 46.

(3) Calculate the mole fraction of ethyl alcohol in each mixture from the relation,

Mole fraction of ethyl alcohol = χ A = ________________________________

(4) Calculate the specific volume, l/d for each mixture.

(5) Enter the results in the tabular form as follows.

(6) Plot a graph of l/d against the mole fraction of ethyl alcohol. Draw smooth curve through

the points. Draw tangent to this curve at a given composition of mixture. Intercepts of the

tangent on χ A

= 0 and χ A

= 1 axis gives the partial specific volumes of water and ethyl

alcohol respectively.

Wt. of liquid x dB

Wt. of water

No. of moles of ethyl alcohol

Total No. of moles water and ethyl alcohol

(P.T.O.)

(7) Ask for the composition of mixture at which partial molar volume is to be determined.

(8) Find the partial molar volume of ethyl alcohol at the given composition of mixture using

the relation,

Partial molar volume = Partial specific volumes x Mol. Wt.

Observation Table

Wt. of empty sp. gravity bottle = ................................. X g

(2) P-8

Liquid/

Bottle

No.

Vol. of

ethyl

alcohol

VA

Vol. of

water

VB

Wt. of

sp. gr.

bottle +

Liquid

Y gm

Wt. of

liquid

(Y-X)

gm

Density

of liquid

= d in

gm/cm3

Wt. of

pure

ethyl

Alcohol

in mix.

WA=V

Axd

A

Moles

of ethyl

alcohol

= nA

Wt. of

water

WB=V

Bxd

B

Moles

of

water =

nB

Mole

Franction

of ethyl

alcohol

= _____

Specific

volume

l/d

nA

nA+ n

B

Pure

Ethyl

alcohol

(A)

1

2

3

4

5

6

7

Pure

Water

(B)

- - dA= - - - - 1

- - dB=1 - - - - 0 1

Results :

Partial molar volume of ethyl alcohol at the given composition of mixture from graph

P-9




To determine the normality of strong acid by titrating it against given strong alkali by

potentiometric method.

Given : Standard 0.2N Strong alkali, 0.1N (approx) strong acid, quinhydrone powder etc.

Apparatus : Potentiometer, platinum electrode, saturated calomel electrode (SCE),

microburette etc.

Procedure : A] Standardise the potentiometer.

B) Potentiometric titration :

1) Pipette out 10 cm3 of given acid solution in a clean beaker, add about

50cm3 conductivity water and a pinch of quinhydrone powder (about

100 mg) and construct the following cell

Θ SCE || Acid (approx 0.1N), quinhydrone | Pt ⊕

2) Stir the solution well and measure the emf of the cell.

3) Add 0.2N strong alkali from burette cm3 by cm3 upto 4.0cm3, stir the

solution each time and measure the emf.

4) After 4.0ml, add alkali with an increment of 0.2cm3 upto 6.0cm3 and then

add with incriments of 1 cm3 up to 10cm3. Stir the solution well and

measure the emf each time.

5) Record the readings in the Observation Table

Observation Table

Sr.

No.

Volume of

0.2N alkali cm3

Observed

emf (E) volt∆Ε ∆cm3 ∆E

∆cm3

Calculations : (a) Plot a graph of emf (E) against volume (cm3) of alkali added. Determine

equivalence point.

(b) Plot second graph of —— against volume (cm3) of alkali added. Determine

the exact equivalence point

(c) Determine the normality of given acid solution using exact equivalence point

from second graph.

Results : (i) Equivalence point from graph (a) = .................. cm3

(ii) Equivalence point from graph (b) = ............. cm3

(iii) Normality of given acid = ............ N

∆ E∆ cm3

P-10



Time : 31/4 hours (New Course) Marks - 25

To determine pH of buffer solutions potentiometrically.

Given : Solution A (Acid) and Solution B (Salt) Solution A-0.2 m CH3 COOH Solution B-0.2

M- CH3 COONa

Apparatus : Potentiometer, saturated calomel electrode (SCE), platinum electrode burettes,

measuring flasks (100cm3), beakers (100cm3)


B) Preparation of buffer solutions :

Prepare five buffer solutions by mixing required volumes of solution A and

solution B in 100 cm3 measuring flasks, as directed by examiner.

Ask for the concentration of A (acid) and B (salt) solutions.

i) Concentration of A (acid) O.2M ii) Concentration of B (salt) O.2M

C) Emf measurements :

1) Take about 50 cm3 of first buffer solution in a clean 100 cm3 beaker, add

a pinch of quinhydrone powder , immerse platinum electrode in it and

connect to SCE using KCl salt bridge. The cell is represented as,

θSCE || buffer soln + quinhydrone | Pt ⊕2) Stir the solution well and measure the emf of the cell (Ec).

3) In a similar way, measure emf values of remaining buffer solutions.

4) Record emf values in the observation table.

Buffer

No.

Observed

Emf

Ec volt

pH from experiment Theoretical value of pH

1

2

3

4

5

Observation Table

(P.T.O.)

Flask

No.

Volume of

solution A cm3

Volume of

Solution B cm3

Conc. of acid in

the buffer soln.

[Acid]

Conc. of Salt in the

buffer soln. [Salt]

1

2

3

4

5

(2) P-10

Calculations :

A) pH from experiment

Observed emf (Ec) of the cell is given by,

Ec = E

Right - E

Left(1)

Ec = E

Q - E

SCE(2)

Ec = Eo

Q - 0.0591 pH - E

SCE(3)

pH = ___________ (4)

Where Eo

Q = 0.6998 V and

ESCE

= 0.2458 V

Calculate pH of all buffer solutions using equation (4)

B) Calculate the concentrations of acid and salt in each of the buffer solution using the equation,

[Acid] = ______________________________________

[Salt] = ___________________________________________________

C) Theoretical pH value

Calculate pH of all buffer solutions using Henderson’s equation,

pH = pKa + log ______

Result :

Eo

Q-E

SCE - E

c

0.0591

Volume of acid taken x conc. of acid taken (0.2)

Total volume of buffer prepared (100 cm3)

Volume of salt solution taken x conc. of salt solution taken (0.2)

Total volume of buffer prepared (100 cm3)

[Salt]

[Acid]

Buffer

No.pH from experiment Theoretical value of pH

1

2

3

4

5

P-11




To determine standard electrode potentials of any TWO electrodes.

Given : 0.1m CuSO4, 0.1m AgNO

3, 0.1m ZnSO

4, conductivity water etc.

Apparatus : Potentiometer, saturated calomel electrode (SCE), KCl salt bridge, KNO3 salt

bridge, electrodes of Cu, Ag, Zn,

Procedure : A] Preparations of solutions :

From a given 0.1m stock solution of metal salt, prepare 0.05m and 0.01m

solutions of each of respective metal salts in 100cm3 measuring flask, using

conductivity water.

B) Standardise the potentiometer

C] Experiment with Electrode 1 : For ex. Copper electrode

1) Construct the copper half cell by dipping a clean copper electrode in

50.0cm3 0.01m CuSO4 solution and connect it to SCE using KCl salt

bridge. A cell is represented as,

Θ SCE || CuSO4 0.01m | Cu ⊕

2) Measure emf (EC) of the cell on potentiometer.

3) Repeat similar experiments with 0.05m and 0.1m CuSO4 solutions

successively and record emf values in a tabular form as given below.

4) Ask for activity coefficient values of CuSO4./AgNO

3/ZnSO

4

Observation Table

Name of Electrode 1 = ...................

Concentration to be prepared Volume 0.1m salt solution

0.05 m 50 cm3 to be diluted to 100 cm3

0.01 m 10 cm3 to be diluted to 100 cm3

(P. T. O.)

Conc

m

Activity

Coefficient

γ

Emf of cell

EC Volt

Electrode

Potential

E volt

Standard Electrode

Potential E0 volt

0.01

0.05

0.10

(2)

D) Experiment with Electrode 2 :

1) Perform similar experiments with electrodes of Ag, Zn, Al in 0.01m, 0.05m and

0.1m solutions of their salts. Construct the cells as follows and measure the emf,

(a) Θ SCE || AgNO3 | Ag ⊕

Here, use KNO3 salt bridge

(b) Θ Zn | ZnSO4 || SCE ⊕

2) Record emf (EC) values in a tabular form as given above.

Calculations :

(a) Emf (EC) of the cell is expressed as,

EC = ERight – ELeft – (1)

Thus, for example, for a cell involving copper half cell

EC = ECu – ESCE – (2)

ECu = EC + ESCE – (3)

Where ESCE = 0.2458 V

(b) ECu = E0Cu + ——— log a

Cu2+ – (4)

E0Cu = ECu – ——— log (m x γ)

(n = 2)

Calculate E0Cu values for 0.01m, 0.05m and 0.1m CuSO

4 solutions and report the mean

value of E0Cu

.

(c) Use equation 1 for all the cells involving Ag, Zn, half cells and accordingly calculate

E0 values.

Results :

(i) Standard electrode potential of electrode 1 = ............... v

(ii) Standard electrode potential of electrode 2 = ............... v

0.0591

n

0.0591

n

P-11

P-12




To determine solubility product and solubility of sparingly soluble salt AgCl

potentiometrically.

Given : 1M KCl, 0.1M AgNO3 etc.

Apparatus : Potentiometer, silver electrodes, KNO3 salt bridge, 100cm3 beakers etc.

Procedure : A] Preparations of KCl solutions :

From 1M KCl solution prepare three dilutions in a 100 cm3 measuring flask

using conductivity water as follows :

B) Standardise the potentiometer.

C] Emf Measurement of the Cell (EC) :

1) Take about 50 cm3 0.1M KCl solution in a clean beaker, immerse Ag

electrode in it and add 2-4 drops of 0.1M AgNO3. Stir the Solution well.

This forms Ag-AgCl half cell.

2) In another beaker, place 50cm3 of 0.1M AgNO3 solution and dip Ag

electrode in it. This forms Ag-Ag+ ion half cell.

3) Combine these two half cells through KNO3 salt bridge to construct the

following cellΘ Ag | AgCl (s) | KCl 0.1M || AgNO

3 0.1M | Ag ⊕

4) Measure the emf of the cell (EC) on potentiometer.

5) Repeat the experiment as described above replacing 0.1M KCl

successively by 0.2M and 0.3M KCl solutions in the left half cell.

6) Emf (EC) values are to be recorded in a tabular form given below

Observation Table

Flask Concn. of KCl Volume of 1M KCl

No. to be prepared

1 0.1 M 10 cm3 diluted to 100 cm3



Conc. of

KCl

M

Activity

Coefficient of

KCl γ

Emf of cell

EC Volt

Activity of Ag+

ion in AgCl

a1

Solubility

Product

KSP

1 0.1 0.770

2 0.2 0.718

3 0.3 0.688

(P. T. O.)

Sr.

No.

(2)

7) Take mean value of KSP to calculate solubility (S) of AgCl

Calculation - (a) Emf of the cell (EC) is expressed as,

EC = ——— log —————— – (1)

EC = 0.0591 log ——— – (2)

EC = 0.0591 [log (aAg

+)2 – log (a

Ag+)

1] – (3)

EC = 0.0591 [log (0.1 x .733) – log (aAg

+)1] – (4)

This can be simplified as,

log (aAg

+)1 = – 1.135 – ———– (5)

Determine (aAg

+)1 values for each concentration of KCl used in left half cell.

(b) Now (aCl

– )1 = (M x γ)

KCl as given in the observation table

(c) KSP

= (aAg

+)1 x (a

Cl–)

1

(d) Solubility (s) = √KSP

mol dm–3

= √KSP

x 143.5 g dm–3

Results :

(i) Solubility product (KSP

)mean = .............

(ii) Solubility (S) = ............. mol dm–3

= .............. g dm–3

0.0591

n

aAg

+ in AgNO3

aAg

+ in AgCl

(aAg

+)2

(aAg

+)1

EC

0.0591

P-12

P-13



Time : 31/4 hours (New Course) Marks - 25

To titrate potentiometrically ferrous ammonium sulphate with potassium dichromate and to

determine redox potential of Fe2+/Fe3+ system.

Given : Standard 0.2N K2Cr

2O

7 and 0.1N (approx) ferrous ammonium sulphate solution,

2N H2SO

4.

Apparatus : Potentiometer, platinum electrode, saturated calomel electrode (SCE), KCl salt

bridge, microburette etc.


B) Potentiometric Titration :

1) In a 100cm3 beaker, pipette out 10cm3 of ferrous ammonium sulphate,

add 20cm3 of 2N H2SO

4 and add 50cm3 conductivity water. Dip platinum

electrode in it and connect this half cell to SCE using KCl salt bridge to

construct the cell,Θ SCE || Fe2+, Fe3+ | Pt ⊕

2) Measure emf (E) of the cell.

3) Add 0.2N K2Cr

2O

7 solution from burette with an increment of 0.5cm3

upto 4.0cm3, then add 0.2cm3 each time upto 6.0cm3. After 6.0cm3, add

K2Cr

2O

7 0.5cm3 each time upto 10cm3.

4) Emf values are recorded in a tabular form as given below

Observation Table

Sr.

No.

Volume of

0.2N K2Cr

2O

7

added cm3

Observed

emf

E volt

∆E ∆cm3∆E

∆cm3

Calculations : (a) Plot a graph (1) of Emf (E) against cm3 of K2Cr

2O

7 added.

(b) Plot a graph (2) of —— against cm3 of K2Cr

2O

7 added.

Determine the exact equivalence point.

(c) Determine emf (Ex) corresponding to half of exact equivalence point, from

Graph (1)

(d) Determine the redox potential of Fe2+/Fe3+ system using equation,

E0

Fe2+/Fe3+ = Ex + ESCE

= Ex + 0.2458

Results : (i) Equivalence point from graph (2) = .................. cm3

(ii) Redox potential of Fe2+/Fe3+ system = ............. V

∆E

∆cm3

P-14




To determine the normality of the given weak acid by titrating it against strong alkali

conductometrically.

Given : 0.1N (approx) weak acid, standard 0.2N strong alkali.

Apparatus : Conductivity bridge, conductivity cell, 100cm3 beaker etc.

Procedure : A) Standardise the conductometer.

B) (1) Pipette out 10cm3 of given 0.1N weak acid solution in 100cm3 beaker,

add 50ml conductivity water, dip the conductivity cell in it and connect it to

conductivity bridge.

(2) Stir the solution well and measure the conductance (C) of the solution.

(3) Add 0.5cm3 of 0.2N strong alkali from burette to the acid solution, stir well

and measure the conductance

(4) In a similar way, measure the conductances after every addition of 0.5cm3

upto 10cm3 of alkali.

(5) Record the readings in tabular form given below.

Observation Table

Sr. Volume of alkali added Conductance (C)

No. cm3 ohm–1

Calculations :

Plot a graph of observed conductance (C) against volume of strong alkali added. From

this graph, determine the equivalence point and calculate normality of the weak acid.

Results :

(i) Equivalence point = ......................... cm3

(ii) Normality of weak acid = ............... N

Or S

P-15




To determine the normalities of strong acid and weak acid in their mixture by titrating it

conductometrically against strong alkali.

Given : 0.1N (approx) Acid mixture, 0.2N strong alkali, conductivity water etc.

Apparatus : Conductivity bridge, conductivity cell, 100cm3 beaker, microburette etc.

Procedure : A) Standardise conductometer.

B) (1) In a 100 cm3 beaker, pipette out 10cm3 of given acid mixture and add

about 50cm3 conductivity water to it. Dip the conductivity cell in it and

connect to conductivity bridge.

(2) Stir the solution well and measure the conductance (C) of the solution.

(3) Add 0.5cm3 of 0.2N strong alkali from burette to the acid mixture, stir well

and measure the conductance

(4) In a similar way, measure the conductances after every addition of 0.5cm3

alkali upto 15.0cm3.

(5) Record the readings in the tabular form.

Calculations :

(a) Plot a graph of conductance (C) against volume of alkali added.

(b) Determine the volumes (Vx) and (Vy) at the two breaks on the graph and calculate

the normalities of strong and weak acids as follows :

(i) Vx = Vol of alkali required to neutralise strong acid.

Normality of strong acid = ————

(ii) (Vy - Vx) = Vol of alkali required to neutralise weak acid.

Normality of weak acid = ——————–

Results :

(i) Normality of strong acid = .......... N

(ii) Normality of weak acid = ............... N

Sr. Volume of alkali added Conductance (C)

No. cm3 ohm–1

0.2 x Vx

10

0.2 x (Vy - V

x)

10

P-16




To study conductometrically the effect of substituent on dissociation constant of weak acid

with respect to acetic acid and monochloro acetic acid.

Given : 0.1N acetic acid, 0.1N monochloro acetic acid, conductivity water.

Apparatus : Conductivity bridge, conductivity cell, measuring flasks (100cm3), beaker

(100cm3) etc.

Procedure : A] Preparations of solutions :

Prepare 0.05N and 0.025N solutions of each acid in 100cm3 measuring flasks

from the given 0.1N stock solutions of acetic acid and of monochloro acetic

acid, using conductivity water, as follows :

B) Conductivity Measurements :

Perform the experiment in two sets as described below :

(a) Set I : For Acetic Acid :

1) Place about 50ml 0.025N acetic acid in 100cm3 beaker, dip the

conductivity cell and connect it to the conductivity bridge.

2) Measure the conductance (C) of the solution.

3) Repeat the measurements with 0.05N and 0.1N acetic acid

solution.

4) Record the results in a tabular form as given below.

Observation Table

Name of the acid = ..........

Cell constant (x) = ........... cm–1 (Given)

Eq. conductance at infinite dilution : (i) Acetic acid λ∞ = 390.72 ohm–1 cm2 and

(ii) monochloro acetic acid λ∞ = 389.52 ohm–1 cm2.

conc. (N) to be prepared Volume of 0.1N acid

0.050 50 cm3 diluted to 100 cm3

0.025 25 cm3 diluted to 100 cm3

1 0.025

2 0.050

3 0.100

Sr.

No.Conc.

N

Observed

conductance

C ohm–1

Sp.conductance

k = x x C

ohm–1 cm–1

Eq.conductance

λ = ————

ohm–1 cm2

1000xk

N

Degree of

dissociation

α = ——λλ∞

Dissociation

constant

Ka = α2. N

5) Ask for the cell constant (x). (P. T. O.)

(2)

(b) Set II : For Monochloro Acetic Acid :

(1) Measure the conductances of 0.025N, 0.05N and 0.1N solutions of monochloroacetic

acid by employing the same procedure as described for set I.

(2) Record the results in a separate observation table as given above.

Calculations :

All the required formulae are given in the observation table itself. Calculate Ka values of

both the acids. Compare them and draw your conclusion.

Results :

(i) Dissociation constant of acetic acid = ...............

(ii) Dissociation constant of monochloro acetic acid = ..............

(iii) Conclusion ............

P-16

P-17




To determine the velocity constant of the hydrolysis of ethyl acetate by NaOH solution by

conductometric method.

Given : 0.05 M NaOH, 0.2 M ethyl acetate (CH3COOC

2H

5) 0.05 M acetic acid

conductivity water etc.

Apparatus : Conductivity bridge, conductivity cell, Volumetric flask (100cm3), beaker, burette

etc.

Procedure : A) Standardise the conductometer.

B) Determination of final conductance (C∞).

Prepare 0.01 M CH3COONa as follows :

Take 20 ml of 0.05 M NaOH in a 100 cm3 Volcemtric flask Add a drop of

Phenolphthalein and add 0.05 M acetic acid from burette till pink colour just

disappears. Dilute the Solution to 100 cm3 Note down it’s condustivity as C ∞

D) Measurement of conductance

1) Prepare following two solutions in two separate beakers.

Beaker 1 : 20 cm3 0.05 M NaOH + 50 cm3 conductivity water

Beaker 2 : 5 cm3 0.2 M CH3COOC

2H

5 + 25cm3 conductivity water.

Keep these two beakers in water bath for about 5 minutes.

Mix the solution from Beaker 1 to Beaker 2 quickly and record the time of

mixing. Measure initian Conductivty as Co. Similarly measure the

conductance of reaction mixture at a regular interval of time, 5, 10, 15, 20, 25

and 30 minutes.

Observations :-

i) Final Conductance of 0.01 M Sodium acetate solution = C∞ = .................. S or ohm-1

(P. T. O.)

(2)

Observation Table

P-17

Sr.

No.

Time in

Minutes

Observed conductance

Ct in S C

t - C∞

1

Ct - C∞

1 0

2 05

3 10

4 15

5 20

6 25

7 30

Calculations : Plot a graph of ______ against t

Calculate k from graph by using formula

k = slope

Results : k by graph =

1

Ct - C∞

P-18




To determine the specific refractivities of pure liquids A and B and of their mixtures and to

determine % composition of the unknown mixture.

Given : Pure liquids A and B, Mixtures (C, D, E) of known compositions and mixture (F)

of unknown composition.

Apparatus : Refractometer, specific gravity bottle (10 cm3).

Procedure : [A] Determination of Densities :

1) Determine the densities of all liquids using specific gravity bottle.

2) Enter the results in Observation Table 1.

Observation Table 1

(P. T. O.)

Liq. Density

d = —————— x dw g/cm3

A

B

C

D

E

F

Dist.

Water dw = 1 g/cm3

Wt of empty sp.

gr. bottle (x)g

Wt of sp. gr.

bottle + liq. (y)g

Wt of liq.

(y-x)gWt. of liq.

Wt. of water

[B] Measurement of Refractive indices (n) :

1) Measure refractive index (n) of each liquid using the refractometer.

2) Record the results in observation Table 2.

3) Ask for known compositions of the mixtures C, D and E.

(2)

Liq. Sp. refractivity

r = ( —––— ) x —

Refractive

Index (n)

A 100 0

B 0 100

C

D

E

F unknown unknown

Observation Table 2

Density (d)

g/cm3 n2 - 1

n2 + 2

1

d

Calculations :

Determine the % composition of mixture F,

(a) By calculation using composition law,

P = [———] x 100

Where P is % of A in mixture F.

(b) By graphical method.

Plot a graph of sp. refractivity (r) against % A and find out % composition of

mixture F.

Result :

% A % B

Composition By calculation By graph

% A

% B

P-18

rF - r

B

rA - r

B

P-19




To determine the molar refractivities of methyl acetate, ethyl acetate, n-hexane and carbon

tetrachloride and calculate the refraction equivalents of C, H and Cl atoms.

Given : Pure liquids - Methyl acetate, Ethyl acetate, n-hexane, carbon tetrachloride.

Apparatus : Refractometer, specific gravity bottle (10ml)

Procedure : [A] Determination of Densities :

1) Determine the densities of all liquids using specific gravity bottle.

2) Enter the results in observation Table 1

Observation Table 1

Density of water (Given) = dw = 1 gm/ml

(P. T. O.)

LiquidsDensity

d = —————— x dwWt of empty sp.

gr. bottle (x)g

Wt of sp. gr.

bottle + liquid =

y gm

Wt of liquid

= (y-x)gmWt. of liq.

Wt. of water

Methyl Acetate

Ethyl Acetate

n-hexane

CCl4

Dist. Water

B) Measurement of Refractive index (n)

1) Measure the refractive index (n) of each liquid using Refractometer

2) Record the results in observation Table 2

3) Ask for the molecular weight of liquid

Observation Table 2

LiquidsMolar refraction

RM

= —— x __Molecular

weight (M)

Methyl Acetate

Ethyl Acetate

n-hexane

Carbon tetra

chloride

Refracti

ve index

(n)

Density

(d) n2-1

n2+2

M

d

(2) P-19

Calculations :

1) Calculate molar refraction for each liquid using formula,

RM

= ____ x __

2) Calculate atomic refractions as follows

a) Molar Refractivity of CH2 group = R

M of Ethyl acetate - R

M Methyl acetate.

b) Atomic Refractivity of H atom = ½ (RM

of n-hexane - 6 x RM

of CH2 group)

c) Atomic Refractivity of C atom = RM

of CH2 group - 2 x Atomic Refractivity of H atom.

d) Atomic Refractivity of Cl atom = ¼ (Molecular Refractivity of CCl4 - Atomic Refractivity of C.

Results :- Atomic refractivities of

i) H atom = -----------------------------

ii) C atom = -----------------------------

iii) Cl atom = ----------------------------

n2-1

n2+2

M

d

P-20




To verify Lambert - Beer law using copper sulphate solution.

Given : Standard solution of CuSO4 (5mg/cm3), 1:1 ammonia solution.

Apparatus : Colorimeter with cuvettes / cells / test tubes, 50ml measuring flasks, micropipette.

Procedure : Part - A : Preparation of CuSO4 Solutions of Different concentrations :

(a) In 50cm3 measuring flasks numbered as 1, 2, 3, 4, and 5, pipette out 0, 2,

4, 6 and 8cm3s of given standard CuSO4 solution respectively.

(b) Add 5cm3 of ammonia (1:1) solution to each flask including unknown

sample and finally add distilled water upto the mark.

Part - B : Determination of λ max (Selection of Proper Filter) :

(a) Use solution containing maximum amount of copper (say 8 cm3) as

Sample and soln in flask No. 1. as blank

(b) Measure an Absorbance or Optical density (O.D.) for the sample using

various filters of known wavelengths.

(c) Record the results in Observation Table 1.

(d) Plot a graph of Absorbance / O.D. against wavelength (λ) and determine

λmax from the maximum of the curve.

(e) Use the filter corresponding to λmax in Part C.

Observation Table 1

Sr. No. Absorbance or O. D.Wavelength of Filter λ nm

Part - C : Measurement of Absorbance / O. D. of CuSO4 solutions :

(a) Use the solution from flask no. 1 (containing no copper) as Blank.

(b) Measure the Absorbance / O. D. of each solution and of unknown sample

at λ max.

(c) Enter the results in Observation Table 2.

(P. T. O.)

(2) P-20

Observation Table 2

Calculations :

(a) Plot a graph of Absorbance (or O. D.) against concentration of copper in mg.

(b) Determine the concentration of copper from the graph.

Results :

(i) λmax = ..........................nm

(ii) Concentration of copper = ............. mg

(iii) Conclusion ...........

Flask

No.

Concentration of Copper

cm3 mg

Absorbance or

O. D.

1 0.0 0.0 0.0

2 2.0 10.0

3 4.0 20.0

4 6.0 30.0

5 8.0 40.0

6 unknown unknown

P-21




To estimate Fe3+ ions by thiocyanate method using colorimeter

Given : Standard solution of iron (0.1mg/cm3), conc. HCl, H2O

2 (20vol), 10% NH

4CNS.

Apparatus : Colorimeter with cuvettes/cells/test tubes, 50cm3 measuring flasks.

Procedure : Part - A : Preparation of Iron Solutions of Different concentrations :

(a) In 50ml measuring flasks numbered as 1, 2, 3, 4, and 5, pipette out 0, 1, 2,

3 and 4ml of given standard solution of iron respectively.

(b) Add 2cm3 conc. HCl, 2cm3 20vol H2O

2 to each flask including unknown

sample. Dilute all solutions approximately to 30 cm3 with distilled water.

Shake well, add 3cm3 10% NH4CNS solution to each flask and finally

dilute up to the mark with distilled water.

Part - B : Determination of λ max (Selection of Proper Filter) :

(a) Use solution containing maximum amount of iron (say 4 cm3) as Sample

and soln in flask No. 1. as blank

(b) Measure an Absorbance or Optical Density (O.D.) for the sample using

various filters of known wavelengths.

(c) Record the results in Observation Table 1.

(d) Plot a graph of Absorbance / O.D. against wavelength (λ) and determine

λmax from the maximum of the curve.

(e) Use the filter corresponding to λmax in Part C.

Observation Table 1

(P. T. O.)

Sr. No. Absorbance or O. D.Wavelength of Filter λ nm

Part - C : Measurement of Absorbance / O. D. of Iron Solutions :

(a) Use the solution from flask 1 (containing no Fe3+ ions) as Blank.

(b) Measure the Absorbance / O. D. of each solution and of unknown sample

at λ max.

(c) Enter the results in Observation Table 2.

(2) P-21

Observation Table 2

Calculations :

(a) Plot a graph of Absorbance (or O. D.) against concentration of iron in mg.

(b) Determine the concentration of iron from the graph.

Results :

(i) λmax =....................nm

(i) Concentration of iron = ............. mg

Flask

No.

conc of Fe3+ ions

cm3 mg

Absorbance or

O. D.

1 0.0 0.0 0.0

2 1.0 0.1

3 2.0 0.2

4 3.0 0.3

5 4.0 0.4

6 unknown unknown

P-22




To estimate Fe3+ ions using salicylic acid by colorimetric titration.

Given : Standard solution of iron, 0.005 M salicylic acid (both solutions prepared in 0.002

M HCl), distilled water etc.

Apparatus : Colorimeter with cuvettes/test tubes, volumetric flasks (100 cm3), burette, pipette,

optical filter etc.

Procedure : 1) Rinse and fill the burette with 0.005 M salicylic acid solution.

2) Dilute the given solution of Fe3+ ions to 250 cm3 with distilled water.

3) Pipette out 10 cm3 of above diluted solution in eleven (11) volumetric flasks.

4) With the help of graduated pipette add respectively 0, 1, 2, 3 ---------, 10 cm3

of 0.005 M salicylic acid to each volumetric flask in serial order. Dilute up to

the mark with distilled water and shake well.

5) Using the solution from flask No. 1, standardize the colorimeter to zero

optical density by using 525 or 530 nm filter.

6) Determine the optical density for each of the solutions using same filter

7) Record observations as given below.

8) Plot a graph of optical density against volume of salicylic acid added. From

the graph find the equivalence point, Vc.

Observation Table

(P. T. O.)

Flask NoOptical

Density

Volume of

Fe3+ ion soln

Volume of

0.005 salicylic acid

1 10 0

2 10 1

3 10 2

4 10 3

5 10 4

6 10 5

7 10 6

8 10 7

9 10 8

10 10 9

11 10 10

(2) P-22

Calculations :-

Since 10 cm3 of diluted solution requires Vc ml of salicylic acid,

250 cm3 of diluted sol will require = (25 x Vc) ml of salicylic acid

Now, 1 cm3 of 0.005 M Salicylic acid ≡ 280 µg Fe3+ ions

Hence, (25 x Vc) cm3 of 0.005 M salicylic acid ≡ 280 x 25 x V

c µgm of Fe3+ ions

Results :

i) Volume of 0.005 M salicylic acid required for complete formation of complex with Fe3+ ions

in 10 cm3 of diluted solution = --------------- cm3

ii) Amount of Fe+3 ions in the given solution =.................... µg

P-23




To determine dissociation constant of acetic acid using pH meter.

Given : 0.1N acetic acid, 0.2N Strong alkali, standard buffer solution of pH 4/7/9.2.

Apparatus : pH meter with glass electrode and saturated calomel electrode (SCE), microburette,

beaker (100cm3).

Procedure : A] Standardise the pH meter using standard buffer solution

B] Acid - Base Titration :

(a) Pipette out 10cm3 of 0.1N acetic acid in a 100cm3 beaker, add to it about

50cm3 conductivity water.

(b) Immerse glass and calomel electrodes in acid solution and connect them

to pH meter. Stir the solution well and measure its pH.

(c) Add from burette 0.5cm3 of 0.2N strong alkali, stir the solution well and

measure pH.

(d) Employ the same procedure of measuring pH after every addition of

0.5cm3 alkali upto 10cm3.

(e) Enter the results in the Observation Table

Observation Table

Sr. No. pHVolume of 0.2N alkali added cm3

Calculations :

(a) Draw a graph of pH against cm3 of alkali added and determine the equivalence point

from it.

(b) Find pH corresponding to half of the equivalence point from the graph and determine

the dissociation constant (Ka) of the acid using the relation,

pH = pKa = – log Ka

Results :

(i) Equivalence point = ................. cm3

(ii) pH at half the equivalence point = ............

(iii) Dissociation Constant (Ka) of the acid = .............

P-24




To determine dissociation constant of malonic acid (Dibasic acid) acid using pH meter.

Given : 0.1 N malonic acid, 0.2 N NaOH and standard buffer solution of pH 4/7/9.2.

Apparatus : pH meter with glass electrode and saturated calomel electrode (SCE), burette,

beaker (100cm3).

Procedure : A] Standardise the pH meter using standard buffer solution

B] Acid - Base Titration :

(a) Pipette out 10cm3 of 0.1N malonic acid in a 100 cm3 beaker, add to it about

50 cm3 conductivity water.

(b) Immerse glass electrode and calomel electrodes in acid solution and

connect them to pH meter. Stirr the solution well and measure its pH.

(c) Add from burette 0.5 cm3 of 0.2 N NaOH, stirr the solution well and

measure pH.

(d) Employ the same procedure of measuring pH after every addition of

0.5cm3 alkali up to 12 cm3.

(e) Enter the results in the Observation Table

Observation Table

Sr. No.Volume of 0.2 N

alkali added cc.pH ∆pH ∆V

∆pH

∆V

Calculations and Graphs :

(a) Draw a graph of pH against the cm3 of alkali added and determine the equivalence point

from it.

(b) Plot another graph of _____ against volume of 0.2 N NaOH added

From the peaks observed in second graph find first equivalence point (V1) and second

equivalence point (V2)

(c) From the first graph of pH against volume of NaOH added find pH corresponding to V½

and pH Corresponding to V1 + _______

pH Corresponding to V½ cm3 is pK1

And pH Corresponding to V1 + _______ cm3 is pK

2

(V2-V

1)

2

(V2-V

1)

2

∆pH

∆V

(P. T. O.)

1) From pK1 and pK

2 calculate K

1 and K

2

pK1 = - log K

1

pK2 = - log K

2

Results :- Dissociation constants of Malonic acid are,

1) K1 = ---------------------------

2) K2 = ---------------------------

(2) P-24


B. Sc. Part-III Chemistry Practical Examination, February/March, 2015

REQUIREMENTS OF THE APPARATUS, CHEMICALS etc.

General :

1. All the necessary equipment, the apparatus, Chemicals etc. required for normal practical work of the above

mentioned class should be made available.

2. Large stock of Distilled Water.

3. Well adjusted good balances, calibrated Weight Boxes with fractional weights, preferably one between two

candidates.

4. Calibrated Burettes and Pipettes.

5. Graduated glassware for Examiners. Measuring flasks, Cylinders. etc.

6. Other Miscellaneous requirement.

Spatulas, blank lables, gum pot, cork opener, glass spoons, rough balances, Kipp's Apparatus (with wash

bottle). glass pencils etc.

INORGANIC EXPERIMENTS

Laboratory Supervisor and/or Head of the Department are expected to see that all the necessary chemicals,

stock/standard solutions, apparatus, glass-wares and related meterials are kept ready on the day of laboratory

inspection for all the inorganic chemistry experiments as per slip Numbers I-2 to I-20.

Requirement of the Chemicals apparaties etc.

Inorganic experiments :

A R Grade Chemicals for Gravimetry : Ferrous ammonium Sulphate, Zinc Sulphate, Barium Chloride, Manganese

Sulphate, potash alum, Nickel Sulphate.

A. R. Grade Chemicals of Cuppor Sulphate, Sodium thiousulphate, Ferrous ammonium Sulphate, Potassium

hydroxide, Nickel Nitrate, Sodium Nitrite, Ammonium thiocynate thiorynate, ammonium dichromate, ammonium

carbonate, cobalt chloride, Nickel chloride, ethylene diammine, thiourea, oxalic acid, Sodium chloride Ponds powder

etc.ORGANIC CHEMISTRY PRACTICALS

1) 0.1N HCl – 5 Litres 2) Approx 0.5N Alcoholic KOH – 3 Litres

3) 1N HCl – 1 litre 4) Fehling Solution A and B – 1 Litre each

5) Appox - 1 N NaOH. - 5 litres 6) Aspirin tablets

7) Bromine in acetic acid 8) KI

9) 10% NaOH 10) 5% NaOH

11) Saturated NaHCO3 Soln. 12) 1 : 1 HCl

(N. B. :– The Quantities of the solutions required will depend upon the numbers of batches to be examined at

the centre. These quantities should be available at the begining of practical examination.)

ORGANIC CHEMICALS

Acetic acid (Pure Glacial), Acetone (pure), Acetanilide, Anthracene, Aspirin, Benzene, Benzoic acid,

Bromobenzene, Benzamide, Carbon tetra chloride, Chloroform, Cinnamic acid, Chlorobenzene, m-dinitrobenzene,

Naphthalene, Alphanaphthol Beta naphthol, Nitrobenzene, o, m, & p-nitro aniline. Oxalic acid, Phthalic acid (Pure

Crystalline), Salicylic acid, Toluene, Ethyl acetate, Ethyl benzoate, Ethyl methyl Ketone, Acetophenonc, Anthracene,

Aniline, p-toluidene, o-toluidene, N-methyl Aniline, Diethyl aniline, urea, Thiourea, Coconut oil, Caster oil,

Groundnut oil, Bromine in acetic acid; Hydroxyl amine hydro chloride, Benzoyl chloride, Picric acid, Phenyl

hydrazine. 2 : 4 Dinitro phenyl hydrazine. N, N-dimethyl aniline; oxalic acid; benzaldehyde, ethylacetoacetale lithium

hydrocide, benzil, furan, maleic 'Potassium bromide, CAN, Fecl3

Some Arrangements for filtration by suction using a Buchner Funnel, and filter flasks should be available for

any candidate who wants it. At least 20 sand baths should be kept ready.

For Estimation :

10 cm3 Measuring Cylinders ... 2

25 cm3 Measuring Cylinders ... 1

500 cm3 Measuring Cylinder ... 1

250 cm3 Measuring Flask ... 1

250 cm3 Conical or F. B. Flasks With corks ... 60

Watch Glass, Small funnel etc.

For Separation :

20 Containers for solid mixtures.

Containers for Liquid mixtures, giass marking pencil,

I lb, bottles, wide mouth 35 capsules marked 'A' Nos. 1 to 35, 'B' Nos. 1 to 35

Other General Requirement for Examination :

Measuring Cylinders : 2000 cm3 (2) 1000 cm3 (2)

500 cm3 (2) 250 cm3 (2)

100 cm3 (2) 150 cm3 (2)

10 cm3 (4)

Measuring Flasks : 1000 cm3 (2) 500 cm3 (2)

250 cm3 with number from 1-35 (two sets)

100 cm3 with numbers from 1-35 (one set),

Flat Bottom Flaks / R. B. Flaks / Conical flasks labelled 'C', 'D' and 'E'

with numbers from 1-35 marked on each set.

Filter Papers, Phenolphthalein, Methyl Orange, Distilling Flaks 50 ml, Air Condensers. Water Condensers, Metal

Cones for drying the ppt., Oil Baths, Thermometers 360 degree, Liquid Paraffin, Funnels Large 6" (4), Spoons, Log

tables and such other Sundry requirements.

REQUIREMENTS FOR PHYSICAL EXPERIMENTS

P2

: 2N Acetic Acid, 1N Acetic Acid, 0.5N Acetic Acid, Pure CCl4, 0.5N NaOH solution, 0.01N NaOH,

phenolphthalein as an indicator.

P3

: 0.5N HCl/0.5N H2SO

4; Methyl acetate, 0.1N NaOH solution, Ice, phenophthalein indicator.

P4 P

5: 0.1N K

2S

2O

8 soln, 0.1N KI soln, 0.002N Na

2S

2O

3 soln, starch solution as an indicator.

P6

: 0.5 N HCl, Methyl acetate, 0.1 N NaOH, Indicator, ice.

P7

: 0.4 MKCl, 0.1 N K2S

2O

8, 0.1 NKI, .002 N Na

2S

2O

3

P8

: Ethyl alcohol.

P9

: 0.1N HCl solution, 0.2N NaOH soln, solid quinhydrone powder; conductivity water.

P10

: Quinhydrone powder, 0.2M Acetic acid - solution A, 0.2M sodium acetate - soln. B. Following is the list of

buffer solutions. From this list, examiner should ask any five buffers to prepare and to determine its pH.

ml of 0.2M Acetic Acid

Solution A

ml of 0.2M Sodium Acetate

Solution B

Approximate

pHSr. No.

1 95.0 5.0 3.46

2 90.0 10.0 3.79

3 80.0 20.0 4.14

4 70.0 30.0 4.38

5 60.0 40.0 4.68

6 50.0 50.0 4.75

7 40.0 60.0 4.82

8 30.0 70.0 5.11

9 20.0 80.0 5.35

10 10.0 90.0 5.50

11 5.0 95.0 6.00

(Note : The molecular weight of crystalline sodium acetate (CH3 COONa ; 3H

2O) is 136, while that of

anhydrous salt is 82)

P11

: 0.1m CuSO4 soln : 24.972 gm of CuSO

4 . 5H2O + 1000.00 ml of conductivity water.

0.1m ZnSO4 soln : 28.761 gm of ZnSO


0.1m AgNO3 soln : 16.989 gm of AgNO

3 + 1000.00 ml of conductivity water.

0.1m AlCl3 soln : 13.334 gm of AlCl

3 (anhydrous) + 1000.00 ml. of conductivity water.

(2)

(3)

Activity coefficients of salt soln.

conc. in molality

(m)

Activity Coefficients (γ1)

CuSO4

ZnSO4

AgNO3

AlCl3 (Theoretical)

0.1 0.15 0.148 0.733 0.528

0.05 0.21 0.202 0.812 0.598

0.01 0.41 0.387 0.892 0.754

P12

: 0.1m AgNO3 : 16.989 gms of AgNO

3 + 1 litre conductivity water.

1m KCl : 74.553 gms of KCl + 1 litre conductivity water

P13

: Std. 0.2N K2Cr

2O

7 soln.

0.1N (approx.) Ferrous ammonium sulphate soln. 2N H2SO

4

P14

: 0.1N (Approx.) Acetic acid soln.

0.2N NaOH soln.

P15

: 0.1N Acid mixture (100ml 1M strong acid + 100 ml 1M weak acid diluted to 1 lit.)

Strong acid : HCl Weak acid : Acetic acid.

P16

: 0.1N Acetic acid

0.1N mono-chloro-acetic acid.

P17

: .05 N NaOH, 0.2 N ethyl acetate (CH3 COO C

2 H

5), 0.5 N acetic acid

P18

: 1) A : Benzene B : Carbon tetrachloride

2) A : TolueneB : Carbon tetrachloride

3) A : Chlorobenzene B : Chloroform.

P19

: Methyl acetate, ethyl acetate, n - hexane, carbon - tetrachloride.

P20

: Std. soln. of copper containing (5mg/ml) : Dissolve 19.646 gms crystalline CuSO4 . 5H

2O in distilled water

using 2 drops of conc. H2SO

4 and dilute to 1 litre.

1 : 1 Ammonia;

P21

: Std. soln of iron containing (0.1 mg/ml) : Dissolve 0.864 gms Ferric amonium sulphate in distilled water and

dilute to 1 litre.

P22

: (i) Iron (ferric alum) solution 2.5 mg/ml Fe+++ in 0.002 M HCl (ii) 0.005 M Salicylic acid in .002 N HCl.

P23

: 0.1N Acetic acid,

0.2N NaOH soln.

std. Buffer solns of pH 4 / 7 / 9.2.

(Buffer tablets are availble commercially)

P24

: 0.1N Malonic acid, 0.1 N NaOH.

o o o


B. Sc. Part-III Chemistry Practical Examination, Feb-March, 2015

DIVISION OF BATCH INTO GROUPS

Principals of the Colleges where the examination is held are requested to put up two notices on the notice

board, one showing the division of each batch of candidates, into three nearly equal Groups A, B and C with their

University Seat Numbers and another showing the scheme of distribution of work amoung these A, B and C groups.

Sd/-

Controller of Exam.

Forwarded with compliment to Principals of the college concerned.


B. Sc. Part-III Chemistry Practical Examination, Feb/March, 2015

DISTRIBUTION OF PRACTICAL WORK

Each batch of the candidates is divided into three groups A, B, C for the Practical Examination and will work

according to the following time table.

Time :- Morning Session (M) – 11.00 A.M. to 2.15. P.M.

Recess 2.15 P.M. to 2.45 P.M.

Evening Session (E) – 2.45 P.M. to 6.00 P.M.

Day Group A Group B Group C

First Day P I O≡ ≡ ≡

Second Day I O P≡ ≡ ≡

Third Day O P I≡ ≡ ≡

P Physical = Instrumental Expt (M/E) + Non-instrumental Expt (E/M)

≡

I Inorganic = Gravimetry + Preparation + Titrimetry (M + E)

≡

O Organic = Mixture Separation (M) + Estimation Preparation and Derivative (E)

≡

N. B. : Candidates must remain present at the centre of the practical examination, atleast 15 minutes before the

commencement of the practical examination. They should bring with them

1) Match box

2) Log table / Calculator

3) Laboratory Journals duly certified

4) One copy of project

5) Apron

Sd/-

Controller of Examination

(2)

Chairman's Adress.

Dr. Suresh S. Patil

Head, Department of Chemistry

PDVP College, Tasgaon

Dist- Sangli


B. Sc. Part-III Practical Examination. CHEMISTRY

CONFIDENTIAL February/March, 2015

Dear Colleagues,

Please find enclosed herewith the following :

(1) i) Programme of practical examination at B. Sc. III February/March, 2015 for the concerned of examiners.

ii) General instructions to examiners.

iii) Practical exercises to be set to the candidates and other relevent papers.

(2) Special instructions :

Your special attention is drawn to the following points :

The first name in the group of examiners indicates Senior Examiner.

i) The Senior Examiner in each group is requested to give general guidance to his colleagues in the conduct

of practical examination.

ii) Before the examination commences the Senior Examiner should kindly see that the arrangements at his

centres are properly made and the programme works according to schedule.

iii) Marks for practical examination should be entered on the answer-books as well as on the marksheets in the

order shown below :

Question 1 Physical 65 Marks

Question 2 Inorganic 70 Marks

Question 3 Organic 65 Marks

Total 200 Marks

For each section marks for all experiments, Journal and oral to be written on the front page.

Marks assigned to the question should be shown in the body of the answer-book. These should be

totalled as marks for the whole question. encircled and transferred on the front page. Total of marks for all

the questions should be transferred to the relevant columns in the Mark Sheets as question 1, 2, 3.

(3) Instructions to Senior Examiner in each group :

Kindly send the following material to the Controller of Exams. Shivaji University, Kolhapur as soon as the

examination is over.

Mark-lists in sealed packet, and

The following papers collected from relevant persons.

(a) Letters from Laboratory Supervisors certifying that :

i) The apparatus used by all concerned with the examination are properly calibrated and the chemicals

supplied are pure.

ii) The laboratory staff working at examination have no relative appearing.

iii) In-organic expert should help physical chemistry expert in preparation of solution.

(b) Absentee report of each centre in duplicate.

(c) A Joint report on the performance of candidates at each centre.

(d) Letter of Authority from your group for altering marks assigned to candidates and for settling marks in the

final meeting.

(e) Report of defficiency of serious nature regarding journals, supply of water, gas, apparatus and chemicals

etc. at your centres.

(f) Marks verification certificates (Practicals) signed by you and your colleagues. These certificates should

essentially indicate the number of candidates examined by you, centrewise.

(g) Submitt the assessed answer book to the Principal of the concerned college.

(4) If the candidates, have performed any experiment by entirely different procedure, they may be allowed to follow

that procedure as alternative method.

(5) The printed copies of question papers will be sent to the different centres by the University Office. One set of

question papers is enclosed herewith for your information. (If any question paper is missing or the number is

short at a particular centre, please dictate or get xeroxed the same from your set.)

(6) If there is any typographical mistake or any mistake due to over sight, kindly bring the same to my notice for

the smooth and efficient conduct of the examinations.

(7) Stamped T. A. and D. A. Bills are to be submitted to the principal of Your College.

(8) The advance receipts for the remuneration of members of your group should be submitted to principal of

concerned practical examination centre.

With kind regards,

Yours faithfully,

Chairman's Address sd/-

Dr. Suresh S. Patil (Chairman)

Head, Chemistry Department,

PDVD College, Tasgaon

Dist. Sangli

Chemistry Practical P-3 Q- 150 nmR>nmoR>nmR>nmoR>nmR>nmoR>nmR>nmoR>nmR>nmoR>

CONFIDENTIAL For Examiners


B. Sc. Part-III Chemistry Practical Examination, February/March, 2015

GENERAL INSTRUCTIONS TO EXAMINERS

1. ALL THE EXAMINERS ARE EXPECTED TO INSPECT THE LABORATORY ON THE DAY OF INSPECTION

ONLY.

2. Principals of the colleges where the examination is held have been requested to put two notices on the board,

one showing the division of each batch of candidates, into three nearly equal groups A, B and C with their

University Seat Numbers and the scheme of distribution of work, among A, B, C groups, Examiners are

requested to check-up whether this is done.

3. All the exercises laid down should be covered wherever possible during the course of examination at a centre.

4. Journals should be collected by the examiners before the commencement of the examination. These should be

examined and initialled by all the examiners.

Marks for Journal and Oral for each section are [ 5 + 5 ].

If candidate submits a lost journal certificate. Zero marks should be assigned. Marks for Journal and oral must

be entered on front page of each section.

5 The Project will be assestes by all the three examiners with eqnal weightage at the time of Practical

examinations.

6. Candidates should not be allowed to refer the journals during the examination. They are, however, permitted to

use Practical Text books. Reference Books and typed manuscripts which do not contain data and results.

7. Candidates should not be allowed to take away their answer-books when they go out for recess.

8. Candidate may not be asked to perform an experiment in Physical Chemistry which he has not carried out, a

revealed from his journal.

9. If the experts' results are not upto the mark, examiners are requested to use their discretion, in assessing the

answerbooks of the candidates.

10. For a batch of students at Physical Chemistry experiments, only one series of Kinetics/Partition experiment

should be set to all the candidates.

11. The candidate may be allowed to use any kind of chemical balance if he/she has used the same throughout the

year and without anybody's help.

12. The candidate may be allowed to use digital instruments, Scientific calculators.

13. A repeator Candidate it any will be allowed to appcar for practical examination Sctem.

7. Std. Electrode potential (P11

)

(i) Observations (for 2 electrodes) (5 + 5) 10

(ii) Calculations of E values 5

E0 values 5

(iii) Accuracy 5

8. Solubility product and solubility (AgCl) (P12

)

(i) Technique 5

(ii) Observations 10

(iii) Calculations Ksp & S 6

(iv) Accuracy 4

9. Redox titration (P13

)

(i) Observations 8

(ii) Graphs (4 + 4) 8

(iii) Calculation of half equivalence pt. 2

Calculation of redox potential (Ex) 3

(iv) Accuracy 4

10. Conductometric titration (P14

)

(i) Observations 12

(ii) Graph 6

(iii) Calculation of normality 3

(iv) Accuracy 4

11. Conductometric Titration (Acid mixture - P15

)

(i) Observations 10

(ii) Graph 4

(iii) Equivalence pt. : strong acid & weak acid (2 + 2) 4

(iv) Calculations (2 + 2) 4

(v) Accuracy 3

12. Conductometry - Substitution effect,hydiolysis of efnyl aeelak (P16

, P17

)

(i) Observations 12

(ii) Calculations (4 + 4) 8

(iii) conclusion 3

(iv) Accuracy 2

13. Colorimetry (P20

, P21

, P

22)

(i) Systematic work 4

(ii) λmax - determination (P20

, P21

) 6

(iii) O. D. determinations for solns. 6

(iv) Graph (Part C) 4

(v) Concn by graph 3

(vi) Accuracy 2

14. pH metry (P23,

P24

)

(i) Technique 4


(iii) Graph 3

(iv) pH at half equivalence pt. 3

(v) Calculation of Ka 3

(vi) Accuracy 2

o o o

(4)

PHYSICAL CHEMISTRY P-24

CONFIDENTIAL For Examiner only


B. Sc. Part-III : Chemistry Practical Examination Feb-March - 2015

(New Course)

PHYSICO-CHEMICAL EXERCISES

1. Instructions to examiners.

2. Physicochemical exercises.

3. Scheme of marking

4. One set of slips of experiments.

PHYSICAL CHEMISTRY

1. INSTRUCTIONS TO THE EXAMINER :

1. Candidates doing physical chemistry experiments will be divided into two groups (I & II

2. Morning Session

Group I will perform Non-instrumental experiments

Group II will perform Instrumental experiments

Evening Session

Group I will perform Instrumental experiments

Group II will perform Non-instrumental experiments

3. Slips of the experiments allotted be pasted on the answerbooks

4. Experiments from instrumental part be allotted by lots.

5. Examiner will collect the required data concerned to the experiment from lab-supervisor.

6. Distribution of marks for physical section :

a) Non-instrumental experiment (Slip Nos. P2 to P8) : 25 Marks

b) Instrumental experiment (Slip Nos. P9 to P

24) : 25 Marks

c) Oral : 5 Marks

d) Journal : 5 Marks

e) Project : 5 Marks

Total : 65 Marks

7. Oral should be related strictly to the experiment(s) allotted to the candidate.

8. Examiner should ask the candidate to calculate k values in kinetic experiment either by calculation or by

graph.

9. Examiner should give the same experiment from non-instrumental part which will be common to all

candidates in the morning as well as in evening session.

2. PHYSICAL CHEMISTRY SLIPS

A) Non-Instrumental :

P1

– General

P2

– P.C. Acetic acid

P3

– Kinetics : Methyl Acetate hydrolysis.

P4

– Kinetics : K2S

2O

8 + KI (Equal)

P5

– Kinetics : K2S

2O

8 + KI (Unequal)

P6

– Kinetics : hydrolysis of methylacetate (two concentrations)

P7

- Kinetics : effect of addition of electrolyte on rate of reaction.

P8

- Partial molar volume of ethyl alcohol.

B) Instrumental :

P9

: Potentiomentric titration (strong acid and strong alkali)

P10

: pH of Buffer solutions (potentiometrically)

P11

: Std. Electrode Potential. (potentiometrically)

P12

: Solubility product and solubility of AgCl. (potentiometrically)

P13

: Redox titration.

P14

: Conductometric titration (Weak acid and strong alkali)

P15

: Conductometric titration (Acid mixture and strong alkali).

P16

: Conductometric measurement of Dissociation Constant of Acetic Acid and monochloro-Acetic

Acid.

P17

: Velocity constant of hydrolysis of ethyl acctate conductometically

P18

: Refractivity (% composition)

P19

: Refractivity (Molar refractivities)

PHYSICAL CHEMISTRY P-24

REQUIREMENTS

P2

: 2N Acetic Acid, 1N Acetic Acid, 0.5N Acetic Acid, Pure CCl4, 0.5N NaOH solution, 0.01N NaOH,

phenolphthalein as an indicator.

P3

: 0.5N HCl/0.5N H2SO

4; Methyl acetate, 0.1N NaOH solution, Ice, phenophthalein indicator.

P4 P

5: 0.1N K

2S

2O

8 soln, 0.1N KI soln, 0.002N Na

2S

2O

3 soln, starch solution as an indicator.

P6

: 0.5 N HCl, Methylacetate, 0.1 N NaOH, Ice, Indicator.

P7

: 0.4 M KCl; 0.1 N K2S

2O

8; 0.1 NKI, 0.002 N Na

2S

2O

3

P8

: Ethyl Alcohol

P9

: 0.1N HCl solution, 0.2N NaOH soln, solid quinhydrone powder; conductivity water.

P10

: Quinhydrone powder, 0.2M Acetic acid - solution A, 0.2M sodium acetate - soln. B. Following is the list of

buffer solutions. From this list, examiner should ask any five buffers to prepare and to determine its pH.

ml of 0.2M Acetic Acid

Solution A

ml of 0.2M Sodium Acetate

Solution B

Approximate

pHSr. No.

1 95.0 5.0 3.46

2 90.0 10.0 3.79

3 80.0 20.0 4.14

4 70.0 30.0 4.38

5 60.0 40.0 4.57

6 50.0 50.0 4.75

7 40.0 60.0 4.92

8 30.0 70.0 5.11

9 20.0 80.0 5.35

10 10.0 90.0 5.70

11 5.0 95.0 6.00

(Note : The molecular weight of crystalline sodium acetate (CH3 COONa ; 3H

2O) is 136, while that of

anhydrous salt is 82)

P11

: 0.1m CuSO4 soln : 24.972 gms of CuSO


0.1m ZnSO4 soln : 28.761 gms of ZnSO


0.1m AgNO3 soln : 16.989 gms of AgNO

3 + 1000.00 ml of conductivity water.

(2)

Activity coefficients of salt soln.

conc. in molality

(m)

Activity Coefficients (γ1)

CuSO4

ZnSO4

AgNO3

0.1 0.15 0.148 0.733

0.05 0.21 0.202 0.812

0.01 0.41 0.387 0.892

P20

: Varification of Beet-Lambert's using copper sulphate solution.

P21

: Estimation of Fe+++ ions by thiocyanate colorimetrically.

P22

: Estimation of Fe+++ ions using salicylic acid by colorimetric titration.

P23

: Dissociation constant of acetic acid using pH meter.

P24

: Dissociation constant of Dibasic acid using pH meter.

P12

: 0.1m AgNO3 : 16.989 gms of AgNO

3 + 1 litre conductivity water.

1m KCl : 74.553 gms of KCl + 1 litre conductivity water

P13

: Std. 0.2N K2Cr

2O

7 soln.

0.1N (approx.) Ferrous ammonium sulphate soln. 2N H2SO

4

P14

: 0.1N (Approx.) Acetic acid soln.

0.2N NaOH soln.

P15

: 0.1N Acid mixture (100ml 1M strong acid + 100 ml 1M weak acid diluted to 1 lit.)

Strong acid : HCl Weak acid : Acetic acid.

P16

: 0.1N Acetic acid

0.1N mono-chloro-acetic acid.

P17

: 0.05 M NaOH; 0.2 M Ethyl Acetate; 0.5 M Acetic acid.

P18

: 1) A : Benzene B : Carbon tetra chloride.

2) A : TolueneB : Carbon tetra chloride

3) A : Chlorobenzene B : Chloroform.

P19

: Methyl acetate; Ethyl acetate; n-hexane; carbon-tetra-chloride.

P20

: Std. soln. of copper containing (5mg/ml) : Dissolve 19.646 gms crystalline CuSO4 . 5H

2O in distilled water

using 2 drops of conc. H2SO

4 and dilute to 1 litre.

1 : 1 Ammonia;

P21

: Std. soln of iron containing (0.1 mg/ml) : Dissolve 0.864 gms Ferric amonium sulphate in distilled water and

dilute to 1 litre.

P22

: (i) Iron (Ferric alum) Solution 2.5 mg/ml Fe+++ in 0.002 M HCl (ii) 0.005 M Salicylic acid in 0.002 M HCl.

P23

: 0.1N Acetic acid,

0.2N NaOH soln.

std. Buffer solns of pH 4 / 7 / 9.2.

(Buffer tablets are available commercially)

P24

: 0.1 N Malonic acid & 0.1 N NaOH.

(3)

3. SCHEME OF MARKING Marks

1. Partition Coefficient (P2 )

(i) Systematic work and Technique 3

(ii) Observation table 2

(iii) Titration readings 10

(iv) Calculations 6

(v) Result and conclusion 4

Total : 25

2. Kinetic (P3

to P7, )

(i) Systematic work & observation table (2 sets) 2

(ii) Titre readings (2 sets) for P4 & P

5 & 12 marks for P

38

(iii) Calculations of initial concentration (for P4 & P

5) 4

(iv) Calculations of k (for 2 sets) 6

(v) Calculation of Ea / Conclusion & acouracy 5

3. Molar volume - (P8)

(i) Calculation of density 7

(ii) Moles of water & ethyl alcohol 7

(iii) Mole fraction, graph, result 8

(iv) Accuracy 3

4. Refractivity (P18

, P19

)

(i) Technique 2

(ii) Density determination 5

(iii) Ref. indices 6

(iv) Calculations of sp. refractivity 2

(v) % composition - by graph (P18

) Calculation only. 5

- by calculation 2

(vi) Accuracy 3

5. Potentiometric Titration (P9)

(i) Observations 10

(ii) Graphs (5 + 5) 10

(iii) Calculation of normality 2

(iv) Accuracy 3

6. pH of Buffer soln. (P10

)

(i) Buffer preparation 5


(iii) Calculations 6

(iv) Accuracy 4



B. Sc. Part-III : Chemistry Practical Examination, February/March, 2015

(NEW COURSE)

INORGANIC CHEMISTRY

1. Instructions to the examiner :

1. All the experiments should be set after consulting with the Laboratory Supervisor.

2. All the experiments should be given at 11.00 a.m.

3. Only one type of gravimetric, only one type of preparation and only one type of titrimetric experiment must

be set for a group of candidates on a particular day.

4. The candidates are expected to perform following experiments and maximum number of marks to be allotted

shall be as follows :

Experiment Marks out of

(a) Gravimetry 25

(b) Preparation 15

(c) Titrimetry 15

(d) Journal 05

(e) Oral 05

(g) Project 05

Total Marks : 70

5. Guidelines for setting the experiments :

A] Gravimetry (Slip No. I-2)

(i) Distribute carefully 20 to 30 cm3 of the stock solution in 250 cm3 measuring flasks marked (G)

using essentially a 50 cm3 burette. OR Distribute 10 to 15 cm3 of the stock solution in 100 cm3

measuring flask marked (G)

(ii) For G4 to G

5 experiments use of sintered glass crucible is expected.

(Counterpoise method should not be allowed)

B] Preparations (slip No. I-3 to I-10)

(i) Preparation of Reineck's and tris (thiourea) Cuprous Sulphatesalt should be set after

consultation with Laboratory supervisor.

(ii) All the masses (weights) should be taken by using rough balance.

(iii) For drying the product use of infra-red lamp, room heater / heating coil as well as heating the

product on a watch glass kept on a beaker containing boiling water is recommended.

C) Titrimetry (slip No. I-11 to I-20)

(i) Percentage purity (Slip No. I-11 to I-14)

Examiner is expected to prepare and distribute at least two samples (mixtures) for a particular

experiment e.g. 60%, 80% etc. preferably using electric mixer.

(ii) Commercial samples (Slip No. I-15 to I-18)

(a) For I-15, at least two commercial samples must be distributed.

(b) For I-14, distributed carefully 20 to 30 cm3 of the stock solution of potash alum in 250 cm3

measuring flasks marked (V)

(c) For I-17, two volumes of milk/lassi are expected to be taken separately by common burette

and analysed. This experiment should be performed simultaneously by all the candidates

and experts as far as possible at the same time preferably at the begining of the evening

session. Examiner should tick-mark ( ) any two volumes on the slip.

(d) For I-18 Boric acid from the market to be given directly. (distribute at least two samples)

(iii) Ion-Exchange Method (I-19, I-20)

For I-19 and I-20, the ion-exchange resin column should be provided in 50cm3 burette with

resin bed approximately 25cm in height. See that the resin columns are properly prepared

(without air bubbles) and are well regenerated and washed before commencement of examination.

Distribute carefully 20 to 30 cm3 stock solution in 100 cm3 measuring flasks marked (v).

INORGANIC CHEMISTRY - A-1

(2)

INORGANIC CHEMISTRY EXPERIMENTS

Scheme of Marking [Total Mark : 65]

A) Gravimetry (Marks : 25)

(a) Error in mass of residue/chelate upto (mg)Marks

Expt. G1 to G

3Expt. G

4 to G

7

± 10 ± 15 15

± 15 ± 20 12

± 20 ± 25 09

± 25 ± 30 06

more than more than

± 25 ± 30 00

(b) Systematic work 05

(c) Method of Calculation 05

B] Preparation (Marks : 15)

(a) Physical appearance (dryness, colour crystalline nature) 05

(b) Practical Yield 05

(c) Systematic Work 03

(d) Method of calculation (irrespective of results) 02

C] Titrimetry (Marks : 15)

(a) Error in burette reading upto (cm3) Marks

± 0.3 08

± 0.5 06

± 0.7 04

more than ± 0.7 00

(b) Systematic work 02

(c) Method of calculation 05

D] Certified Journal (Marks : 5)

E] Oral (Marks : 5)

Short answer questions related to the experiments are expected including related theoretical background. Oral

should be covered within 10 minutes.

F) Project - Short answer question related to the project subject are expected.

Note : All the examiners are requested to see that :

(i) all the chemicals, glass-ware, apparatus and standard / stock solutions required for inorganic experiments

are kept ready on the date of inspection.

(ii) Stock solutions for gravimetry, titrimetry and samples for % purity experiments are to be prepared by the

inorganic examiner on the date of inspection.

Preparation of Stock Solutions

A] Gravimetry :

(1) By using silica Crucibles

G1

: Estimation of Fe as Fe2O

3

FeSO4 (NH

4)2 SO

4 . 6H

2 O 200g

CuSO4, 5H

2O 20 g diluted to 1 dm3

H2SO

4 (Conc.) 10cm3

G2

: Estimation of Zn as Zn2 P

2 O

7

ZnSO4 . 7H

2 O 110g

FeSO4 . (NH

4)2 SO

4 . 6H


INORGANIC CHEMISTRY - A-1-2

H2SO4 (Conc.) 5 cm3

G3

: Estimation of Ba as BaSO4

BaCl2 , 2H

2O 50 g

FeCl3 . 6H


HCl (Conc.) 10 cm3

(2) By using sintered Glass Crucible

G4

: Estimation of Ba of BaCrO4 (Crucible Grade G-4)

BaCl2 , 2H

2O 40 g

FeCl3 . 6H

2O 15 g diluted to 1dm3

HCl (Conc.) 5 cm3

G5 : Estimation of Ni as Bis - (dimethyl glyoximato) nickel (II) (Crucible Grade G3)

(a) NiSO4 . 7H

2O 40 g

(NH4)2SO

4 . Fe

2 (SO

4)3 . 24H


H2SO

4 (Conc.) 5 cm3

OR

(b) NiCl2 , 6H

2O 35 g

FeCl3 , 6H


HCl (Conc.) 5 cm3

N.B. : Please note, the use of Conc. HNO3 must be avoided for (G5 - Ni) experiment.

B] Inorganic Preparations

All the chemicals of A. R. grade and in sufficient quantities as per requirements, according to I-3 to I-11 must

be made available.

C] Titrimetry

(i) While preparing the sample mixture for estimation of percentage purity - (for I-11 to I-14) the neutral salt

such as sodium sulphate or potassium sulphate is to be used.

(ii) For I-15, Pond's (Magic), Pond's (Dreamflower) or the sample which has been previously analysed may be

supplied for examination.

(iii) For I-14 (Potash Alum), prepare the stock solution as follows : 35g K2SO

4 . Al

2 (SO

4)3 . 24H

2O (A. R. Grade)

should be dissolved along with few drops of conc. H2SO

4 in deionized water and diluted to 1 dm3.

(iv) For I-17 (Acidity of Milk/Lassi), sample of cow or bufallow milk or lassi must be stored in refregerator prior

to distibution for analysis. See that it is well stirred and free of air while distributing to the candidates.

(v) For I-18 - Boric acid from the market to be given directly.

(vi) For I-19 (Sodium by Ion Exchange) :

100g common salt (A.R.) dissolved in deionized water and diluted to 1 dm3.

(vii) For I-20 (Mg (II)/Zn II by Ion Exchange)

(a) Dissolve 12g magnesium and 20g zinc metal in minimum amount (A.R.) conc. HCl and dilute to

1 dm3 with deionized water.

(b) Dissolve 20g MgO and 25g ZnO of A. R. grade in minimum amount (A.R.) Conc. HCl and dilute to

1 dm3 with deionized water.

(c) Dissolve 40g MgCO3

and 40g ZuCO3

of A.R. grade in minimum amount of (A.R.) conc. HCl and dilute

the solution to 1 dm3 using deionized water.

(viii) For I-18 (Percentage of boric acid)

Use commercial Sample of Boric acid (Boric Powder) as it is.

(3)

INORGANIC CHEMISTRY - A-1-2

ORGANIC CHEMISTRY NEW - 1

(4)

(4) Scheme of Marking

Organic Exercises Total Marks : 65

1) ORGANIC QALITATIVE ANALYSIS - Marks - 25

(For solid - solid mixtures)

1. Reporting the type of the Mixtare 5

2. Neat separation of the components 3

3. Identification of the two components

a) Preliminary tests (Nature, colour, odour, effect of heat etc.) 2

b) Detection of elements 4 - 4

c) detection of Functional group 3 - 3

d) Melting points (Boiling points in case of liquids) 4 - 4

e) Correct identification 2 - 2

f) For writing the correct structures 2

(For Liquid - solid and liquid - liquid mixture)

1) Reporting the nature of mixture 2

2) Neat seperation of components 6

3) Identification of the two components as per given for solid-solid mixture

2) ORGANIC ESTIMATION - Marks 20

1. Systematic work 4

2. Accuracy of bueret readings 12

3. Reactions 1

4. Calculations 3

Error in Titre - Marks - 12

± 0.2 ml 12

± 0.3 ml 10

± 0.4 ml 8

± 0.5 ml 6

± 0.6 ml 5

± 0.7 ml 4

± 0.8 ml 3

3) ORGANIC PREPARATION - Marks 20

1. Physical appearance (dryness, colour crystalline nature) 5

2. Practical yield 5

3. Reactions and mechanism 3

4. Calculation 3

5. TLC Preparation 4

4) Derivative - Marks - 5

1. Method of preparation & reaction 1

2. Recrystallisation, Selection of proper Solvent 1

3. Physical nature / Apperance of the derivative 1

4. Correct M. P. 2

Oral – Marks - 5

Journals Marks - 5

5) Oral - (N. B.)

Short answer questions to be asked related to the experiments regarding organic mixture separation,

estimation and preparation of derivative.

o o o



B. Sc. Part-III : Chemistry Practical Examination, February/March, 2015

ORGANIC CHEMISTRY

1. Instructions to the Examiner

2. Mixtures for Separation.

3. Exercises in Estimations and Preparation

4. Scheme of marking

5. One set of slips of Experiments

ORGANIC EXERCISES

(1) Instructions to Examiners :

The candidates are expected to perform following experiments. The maximum number of marks to be allotted

shall be as follows :

Experiment Marks out of

(a) Qualitative analysis 25

(b) Organic Estimation 20

OR

(b) Organic preparation

(c) Preparation of derivative 05

(d) Journal 05

(e) Oral 05

(f) Project 05

Total 65

1. The same mixture should not be given to more than one candidates in the same group.

The candidates are required to separate the components of the mixture, to identify the components

and submit the answer-book by 2.15 p.m.

The candidates should be asked to report within first half an hour the type of the mixture. He/She

should then be asked to explain the procedure he/she is going to adopt for separation. If he/she is on the

wrong track, he/she may be told the method of separation and 4 marks may be deducted for this.

2. Organic Estimation or Preparation should be given at 2.45 p.m.

3. Preparation of derivative of the following organic compounds. One of the following derivative may be

asked to prepare to each candidate.

i) Oxime derivatives of acetone, or, acetophenone

ii) Benzoyl derivative of β-naphthol or Aniline.

iii) Picrate derivative of β-Naphthol or Anthracene

iv) Anhydride of Phthalic asid

v) 2 : 4 DNP of acetophenone or acetaldehyde

vi) Urea oxalate

Here name of derivative should be mentioned on the slip. Name of Organic Compound shold not be given

on slipWherever necessary the conditions for the preparation of the derivative such as solvent,

temperature, etc. may be given to the candidate. This exercies should also be given at 2.45 p.m.

4. Substances involving hydrolysis should be given to the candidates and experts in round bottom flask.

(2) Organic mixtures for separation :

N. B. : i) For solid-liquid and liquid liquid mixtures avoid detection of type of mixture. Instead the weightage is

given to detection of nature of mixture and seperation of mixture.

ii) Crystalline phthalic acid must be used in mixtures and m.p. of the acid must be checked.

iii) The two components in each mixture should be in about 1 : 1 proporation.

iv) All the mixtures must be prepared according to the list given below.

v) Liquid - Liquid and Liquid - Solid mixtures should be prepared fresh on the day of Examinations.

vi) No mixture should be repeated in the same group.

List of organic mixtures

ORGANIC CHEMISTRY NEW - 1

Solid - Solid Nature

1) Aspirin + Naphthalene

2) Phthalic acid + O-Nitroaniline

3) Benzoic acid + Beta Naphthol

4) p-Nitroaniline + Alpha Naphthol

5) m. Dinitrobenzene + m-Nitroaniline

6) Beta Naphthol + Acetanilide

7) Cinnamic acid + Acetanilide

8) Salicylic acid + p-Nitroanilince

9) Phthalic acid + Alpha - Naphthol

10) m-Nitro aniline + Beta Naphthol

11) Acetanilide + O-Nitroaniline

12) Alpha Naphthol + Naphthalene

13) Aspirin + Acetanilide

14) Salicylic acid + O-nitroaniline

15) Benzoic acid + Alpha-Naphthol)

16) Cinnamic acid + m-Dinitrobenzene

Solid - Liquid Nature

17) Acetone + m-dinitrobenzene

18) Acetone + Acetanilide

19) Chloroform + Thiourea

20) Acetone + Oxalic acid

21) Ethyl acetate + Naphthalene

22) Carbon tetrachloride +urea

Liquid - Liquid Natures

23) Acetone + Nitrobenzene

24) Ethyl acetate + aniline (freshly distilled)

25) Carbon tetrachloride + Nitrobenzene

26) Chloroform + Accetophenone

27) Chloroform + Bromobenzene

28) Ethyl acetate + N-N-dimethyl aniline

29) Ethyl benzoate + Chloroform

30) Ethyl acetate + Nitrobenzene

31) Acetone + o-toluidene

(3) Organic Estimations :

i) Estimation of cane sugar by using Fehling solution :

Prepare 3% solution of cane sugar in water.

Distribution : 20 to 30 ml.

Requirements : A solution of 1NHCl

Fehling Solution-A, Fehling solution-B, 2% Potassium Ferrocyanide indicator in 10% acetic acid to be

prepared fresh when required, 1% methylene blue solution in water.

Note :- Fehling solutions (A & B) should be taken by separate burette.

ii) Saponification value of an oil.

1. 0.5N alcoholic KOH solution (approx)

2. 0.1N HCl (Exact solution).

3. 10% solution of an oil in alcohol

(2)

ORGANIC CHEMISTRY NEW - 1-2

(50gms of oil is dissolved in absolute alcohol) making the volume to 500 ml absolute alcohol. Distribute

8ml, 10ml, 12ml to each student in round bottem flask for refluxion.

Volume weight distribution.

8 ml of oil soln will contain 0.8 gm of oil.

10 ml of oil soln will contain 0.1 gm of oil

12 ml of oil soln will contain 1.2 gm of oil.

(Expected sap-value for the following oils)

1. Coconut oil 250–260

2. Castor oil 177–187

3. Ground nut oil 189–196.

Any one of the following oil may be given.

Coconut oil, Caster oil, Ground nut oil

iii) Estimation of aspirin :

Requirement : Aspirin tablets

approx. 0.1 N NaOH solution 4 lit.

Solid oxalic acid

Phenolphthalein indicator.

iv) Estimation of Acid and Ester :

Dissolve 10 g of benzoic acid and ethyl benzoate or methyl benzoate in minimum quantity of rectified spirit in

two separate beaker. Pour the two solution in measuring flask and dilute to 1 liter with distilled water.

Distribution : 15, 20, 25 ml in measuring flask and round bottom flask for blank and back titration respectively.

Requirement : approx. 1 N NaOH solution 4 lit.

Solid oxalic acid

Phenolphthale in indicator.

(4) Preparation

i) Preparation of dihydropyrimidinone

ii) Preparation of 1.1,2-Bis-2-naphthol

iii) Preparation of dibenzalpropanne

iv) Preparation of Diels-Alder adduct.

v) Preparation of Benzilic acid

vi) Preparation of P-Bromoacetanlide.

N. B. Give 1-2 gm of subsfrate to each student.

(3)

ORGANIC CHEMISTRY NEW - 1-2



B. Sc. Part-III : Chemistry Practical Examination, March, 2010

AUTHORITY

We hereby authorise the Chairman B. Sc. Part-III Chemistry (Principal) Practical Examination, March, 2006 to

make corrections in the mark-lists, if necessary, and to settle the marks at the final meeting.

Name of the examiner Signiture

(i)

(ii)

(iii)

Date : ...............................................

Place : ...............................................

CERTIFICATE OF VERIFICATION OF MARKS

(To be attached to the mark-sheets to which it relates)

I hereby, certify that I have verified the entries of marks in the mark-sheets with the entry of marks on the

Answer-books in the subject of CHEMISTRY (Practical) at the B. Sc. Part-III Examination, and have found them to be

correct.

I further certify that the totals entered in these mark-sheets have been checked by me and have been found

correct. The total No. of Answer Papers/Sections assessed by me is

only. (Give centerwise report.)

Date : ...............................................

Place : ...............................................

Name of the examiner Signiture

(i)

(ii)

(iii)

O-1 (Mixture)


B. Sc. Part-III / Chemistry Practical Examination, Feb./March, 2015

Time : 3 ¼ hours) (Marks 25

Separation of Organic mixture

You are given a mixture of two Organic substances in a container marked (A)

bearing your table number Report within first half an hour, the type of mixture, then

separate the components of the mixture and identify, them. Show the melting points

or boiling points to one of the examiners and take his signature on them. Show the

pure specimens of the substances to the examiner.

N. B. : Preserve the components of the mixture.

Components of the given Mixture are

(1) .........................

(2) .........................

O-2 (Cane sugar)




Organic Estimation

Estimation of Cane Sugar by using Fehling Solution

In a 250 cm3 round bottom flask, marked ‘C’, bearing your table number, you are

given a solution of cane sugar. Estimate the amount of sugar in it. Submit your results

in the tabular form given below. You are given the following solutions :--

1. 1N HCl

2. Fehling solutions (A & B)

Instructions :

Reflux the cane sugar solution with 5 cm3 of 1 N HCl, on water bath for half an

hour On cooling neutralise the excess acid by solid Na2CO3 and dilute to 250 cm3 in a

measuring flask. with distilled water

Take 10 cm3 of the Fehling solution (5 cm3 each of A & B from separate burette) in

a porcelain dish. Add one test tube of distilled water to it and heat to boiling. Titrate

the boiling Fehling solution against refluxed diluted sugar solution from the burette

using methylene blue / K4 Fe (CN)6 as indicator.

Tabular form of Results

1. 10 cm3 of Fehling solution require ............... cm3 of hydrolysed sugar soln.

2. The Quantity of sugar in the given solution ................ g. ........................... 10-3 kg.

O-3 (Saponification)




Organic Estimation

Saponification value of an oil

In a 250 cm3 round bottom flask marked ‘C’ bearing your table number, you are

given a solution of an oil containing ............... gm of oil. Determine the Saponification

value of the given oil.

You are given the following solutions :

1. Approx 0.5 N Alcoholic KOH Solution.

2. 0.1 N HCl Solution in flask marked ‘E’.

Instructions :

1) Saponification and Back Titration

To the given amount of the oil, add 25cm3 of given 0.5 N alcoholic KOH from the

burette Reflux the reaction mixture on a water bath for 1½ hours. After complete

Saponification (hydrolysis) cool and transfer the contents to 100 cm3 measuring flask

and dilute the solution to 100 cm3. with distilled water. Pipette out 25cm3 of this

refluxed diluted Solution and titrate it against 0.1 N HCl using Phenolphthalein as an

indicator for estimating the unused KOH Solution.

2) Blank Titration.

Dilute, 25cm3 of given 0.5 N alcoholic KOH Solution, to 100 cm3 with distilled

water. Titrate 25 cm3 of this diluted solution against 0.1 N HCl Solution using

phenolphthalein as an indicator

Enter your results in the following form.

Results :-

1) Quantity of alcoholic KOH Solution required in terms of 0.1 N HCl for Saponification

of given oil = .................... cm3.

2) Saponification value of the given oil = ................

(N. B. :- Ask for weight of the oil for calculations).

O-4 (acid-ester)




Organic Estimation

Estimation of Acid and Ester

In a 250 cm3 round bottom flask and measuring flask, marked ‘C’ and ‘D’ bearing

your table number, you are given a solution of acid and ester mixture. Estimate theamount of acid and ester present in it. Submit your result in the tabular form given

below. You are given the 1 N NaOH (approx) solution.

1) Standardisation of given NaOH solution

Prepare 250 cm3 0.1 N oxalic acid solution.

Dilute 25 cm3 of given NaOH solution with distilled water to 250 cm3 in measuringflask and titrate 25 ml of this diluted solution against 0.1 N oxalic acid solution.

2) Estimation of Acid in Mixture

Dilute the given acid ester mixture to 250 cm3 with distilled water. Titrate 25 cm3

of this diluted solution against above diluted NaOH solution. in step 1

3) Estimation of ester

Reflux the given acid ester mixture with 25cm3 appox. 1 N NaOH for 2 hours On

Water bath and Dilute the reaction mixture With distilled water to 250 cm3 inmeasuring flask. Titrate the 25 cm3 of this diluted solution against 0.1 N oxalic

acid solution.

Results

1. Exact normality of given NaOH Solution = ...........................

2. Amount of acid in the acid ester mixture = ..........................

3. Amount of ester in the acid ester mixture = .........................

O-5 (aspirin)




Organic Estimation

Estimation of Aspirin

Preparation of standard solution of oxalic acid

Prepare 100 cm3 0.1 N Oxalic acid solution. using didtilled water

Standardisation of given NaOH

Pipette out 10 cm3 of 0.1 N oxalic acid and titrate with 0.1N NaOH (approx) from

burette. Calculate normality of NaOH

Estimation of Asprin

Weigh accurately the given tablet. Dissolve it in minimum amount of alcohol and

transfer it to 100 cm3 volumetric flask and make its volume 100 cm3 by alcohol. Take

10 cm3 of this diluted solution by pipette and titrate it against 0.1N NaOH solution

using phenolphthalein as an indicator.

Result :

1. Exact normality of given NaOH solution = ---------------

2. Amount of aspirin in given tablet = ------------ gm. -------------- 10-3 kg.

3. % of aspirin in given tablet = --------------- gm ---------------- 10-3 kg.

O-6 (aspirin)




Organic Preparation

Preparation of

Dihydropyrimidinone

Take equimolar mixture of benzaldehyde, ethyl acetoacetate and urea in a round bottom

flask and shake by hand for 2 minutes. Heat the reaction

mixture in a water bath at 90 °C for one hour. With progress of the reaction a solid started to

deposit and after one hour the flask is full of solid. Collect the product in a conical flask

carefully with a spatula and wash with cold water (1 ml) and then r ecrystallize from rectified

spirit to obtain a colorless solid, dry and weigh it. Take the m. p. of recrystallized product and

confirm byTLC.

Results :

1. Wt. of the crude product =.......... gm. =....... 10_3 kg.

2. Percentage practical yield of product =.......%

3. Physical constant of the product =........ °C = ......... K.

4. Rf value of the product =..........

O-7 (m-nitroaniline)




Organic Preparation

Preparation of 1,1,2 Bis napthol

In an porcelain mortar pestle, take a mixture of given amount of 2-naphthol and iron(III)

chloride with 2 drops of water and grind for about 20 minutes. Allow the mixture to stand

for about 2 hrs with a little grinding now and then. Then transfer the mixture into a 100

ml beaker with water (40 ml) and boil for 10 -15 minutes. After cooling, the solid will be

separated, filter, wash with boiling water (10 ml), recrystallize from toluene, dry and weigh

it. Take the m. p. of recrystallized product and confirm by TLC.

Results :

1. Wt. of the crude product = .......... gm. =....... 10 _3 kg.


3. Physical constant of the product =........ °C =......... K.


O-8 (m-Dinitrobenzene)




Organic Preparation

Preparation of Dibenzalpropane

In a 25 mL round bottom flask containing a small magnetic bar, take given

amount of mixture of benzaldehyde, acetone in ethyl alcohol and add sufficient amount

of lithium hydroxide monohydrate to it. S tirr the reaction mixture vigorously for 8 -10 minutes

due to which the pale yellow solid will precipitate out. Add 5 g of crushed ice to settle

down the solid product. Filter the precipitated pale yellow solid, wash with water,

recrystallize with ethanol, dry and weigh it. Take the m. p. of recrystallized product and

confirm by TLC.

Results:

1. Wt. of the crude product =.......... gm. =....... 10 _3 kg.


3. Physical constant of the product =........ °C = ......... K.


O-9 (p-Bromoacetanilide)




Organic Preparation

Preparation of Diels-Alder adduct

Results:

1. Wt. of the crude product = .......... gm.= ....... 10 s_3 kg.


3. Physical constant of the product = ........ °C= .........K.

4. Rf value of the product = ..........

In a round bottom flask, shake or stir the mixture of given amount of furan and maleic acid in

water for 2-3 hrs at room temperature. Filter the adduct formed and wash with water,

recrystallize from aqueous ethanol, dry and weigh it. Take the m. p. of recrystallized product

and confirm by TLC.

O-10 (p-idonitrobenzene)




Organic Preparation

Preparation of Benzilic acid

Grind the given amount of benzil thoroughly with sufficient amount solid NaOH or

KOH in a dry mortar with the help of a pestle to make an easy flowing powder. Then transfer

this material subsequently into a dry conical flask fitted with a piece of cotton at its mouth

and heat on a boiling water-bath for 20 minutes. Then cool the mixture to room temperature,

dissolve in minimum amount of water and acidified the aqueous solution with conc.

HC1 with thorough cooling in ice. Filter the precipitated product, wash with cold water and

crystallize from hot water, if needed, dry and weigh it. Take the m. p. of recrystallized

product and confirm by TLC.

Results:

1. Wt. of the crude product = .......... gm.= ....... 10 _3 kg.


3. Physical constant of the product =........ °C =......... K.

4. Rf value of the product = ..........

O-11 (benzene azo-βnaphthol)




Organic Preparation

Preparation of p-Bromoacetanlide

In a 250 ml conical flask, dissolve given amount of acetanilide in ethanol. Prepare the

solution of potassium bromide and ceric ammonium nitrate with sufficient quantity in

water. Transfer this solution into an addition funnel. Add this solution to the conical flask

containing acetanilide solution drop wise. After completion of the addition, stir the reaction

mixture for 10 minutes at room temperature. Pour the solution into ice-cold water. Filter the

white crystals separated through Buchner funnel, dry and weigh it. Take the m. p. of

recrystallized product and confirm by TLC.

Results :

1. Wt. of the crude product =.......... gm. = ....... 10 _3kg.


3. Physical constant of the product = ........ °C = ......... K.


O-12 (Derivative)



(Marks 5

Preparation of Derivative (Along with other exercise)

Prepare ................................. derivative of ......................... supplied to you in a container

marked ‘B’ bearing your table number.

Give a method of preparation and reaction for the derivative.

Pure specimen of the derivative should be shown to the examiner. The M. P. of the

derivative should be initialled by one of the examiners.

Recrystallise the derivative using suitable solvent.

M. P. of the derivative ....................... 0C.

...................... K

(General) I-1


B. Sc. Part-III : Chemistry Practical Examination, Feb./March, 2015

Time : 6 ½ hours)

Inorganic Analysis

General Instructions to the Candidates :

1. Credit will be given for neat and systematic work.

2. All masses and volumes should be directly entered in the answerbook.

3. All masses and volumes should be initialled by one of the examiners as soon as

they are taken.

4. Use only the balance bearing your table number. The candidate may use any

type of chemical Balance if he/she has used the same (without anybody’s help)

through out the year.

5. Credit will be given for details of all types of calculations.

6. Procedure should not be written for any experiment.

7. Results should be written at the end of calculations as per slip.

8. S. I. units should be followed as far as possible.

(Gravimetry) I-2



Time : 6 ½ hours) (Marks : 25

Gravimetric Estimation

In the 250 cm3 (or 100 cm3) measuring flask, marked (G), bearing your table number you are

given a solution to determine gravimetrically the amount of -

-G1- Iron as Fe2O

3 from ferrous ammonium sulphate, copper sulphate and free sulphuric acid.

-G2- Zinc as Zn2P

2O

7 from zinc sulphate, ferrous ammonium sulphate and free sulphuric acid.

-G3- Barium as BaSO4 from barium chloride, ferric chloride and free hydrochloric acid.

-G4- Barium as BaCrO4 from barium chloride, ferric chloride and free hydrochloric acid.

-G5- Nickel as [Ni(C4H

7O

2N

2)2] bis-(dimethyl glyoximato) nickel (II), from nickel sulphate, ferric alum

and free sulphuric acid.

Instructions :

1) Dilute the given solution to 250 cm3 (or 100 cm3) with distilled water and use 50cm3 of the

diluted solution for the estimation.

2) Use sintered glass crucible for experiments from G-4 to G-5.

3) Calculate the amounts of metal and metal salt Using the appropriate Gravimetric Factors:

G1 : Fe2O

3: 2Fe : 2 FeSO

4 . (NH

4)2 SO

4 , 6H

2O ≡ 1 : 0.6994 : 4.911

G2 : Zn2P

2O

7: 2Zn : 2 ZnSO

4 , 7H

2 O ≡ 1 : 0.4291 : 1.886

G3 : BaSO4

: Ba : BaCl2, 2H

2 O ≡ 1 : 0.5884 : 1.0467

G4 : BaCrO4

: Ba : BaCl2 , 2H

2O ≡ 1 : 0.5426 : 0.9651

G5 : Ni (C4H

7O

2N

2)2

: Ni : NiSO4 . 7H

2 O ≡ 1 : 0.2032 : 0.9721

Results : Present your results in the following tabular form

1) 50cm3 diluted solution ≡ ............. g of residue / chelate. (of .............. ) ≡ ............. x 10-3 kg

2) Quantity of metal in the given solution ≡ ............. g (of .............. ) ≡ ............. x 10-3 kg

3) Quantity of metal salt in the given solution ≡ ............. g (of .............. ) ≡ ............. x 10-3 kg

(Preparation - P1) : I-3




Preparation of Sodium cuprous thiosulphate

(3Cu2S

2O

3 . 2Na

2S

2O

3 . 6H

2O)

Dissolve 5g of copper sulphate in 25cm3 warm distilled water and 9.0 g of

sodium thiosulphate in 15 cm3 warm distilled water. Adjust the temperature of both

solutions to about 400C (313K). Add slowly, with constant stirring, the sodium

thiosulphate solution to copper sulphate solution.

A bright yellow crystalline product will separate out. Leave the product for an

hour.

Filter on Buchner funnel and wash it with cold water followed by a few cm3 of

acetone.

Dry the sample below 500 C (323K) and weigh on a rough balance.

Calculate theoretical and practical percentage yield. Present your results as follows :

Results :

(1) Yield of the product = .................... g. = ............. x 10-3 kg

(2) Theoretical yield of the product : ...................... g. = ............. x 10-3 kg

(3) Practical percentage yield of the product = .................. %





Preparation of potassium trioxalatoferrate (III).

K3 [Fe (C

2 O

4)3], 3H

2O

Step I : Preparation of ferrous oxalate :

Dissolve 8.0 g crystalline ferrous ammonium sulphate in about 25cm3 of hot

distilled water. Acidify it with about 1cm3 2N H2SO

4. To this solution, add about 40

cm3 of 10% solution of oxalic acid, slowly with constant stirring.

On low flame, heat the reaction mixture very slowly, nearly to boiling, cool the

solution. Yellow crystals of ferrous oxalate will separate out. Decant off the upper clear

liquid. Shake the yellow solid with 50 cm3 of hot distilled water. Decant off the clear

liquid. Filter and wash the product on Buchner funnel with hot water followed by

acetone.

Step II : Preparation of ferrioxalate :

Dissolve 5g of potassium oxalate, (K2C

2O

4 , H

2 O), in about 20 cm3 of warm distilled

water. Now suspend the entire quantity of ferrous oxalate, in the warm solution of

potassium oxalate. Stir well. Place the beaker in hot water bath at about 400 C (313K) and

slowly add 15cm3 of “20vol.” H2O

2 from the dropping burette. Ferrous iron will get

oxidised to ferric iron. Stir the solution. Heat the solution nearly to boiling and add about

10cm3 of 10% oxalic acid, drop by drop, with constant stirring. Avoid excess of oxalic

acid.

Filter the solution and to this hot filtrate add about 15cm3 of ethanol. Heat the

solution gently and dissolve the precipitate. Keep the solution in a dark cupboard and

allow the product to recrystallize.

Filter and wash the product with (1 : 1) ethanol and finally with acetone, on a

Buchner funnel. Dry the product and weigh it on a rough balance.

Calculate theoretical and Practical percentage yield of the product. Present your

results as follows :

Results :


(2) Theoretical yield of the product = ....................... g. = ............. x 10-3 kg

(3) Practical percentage yield of the product = ...................... %





Preparation of Potassium trioxalatoaluminate (III)

K3 [Al (C

2 O

4)3], 3H

2O

Weigh 1.0 g. aluminium sheet/wire and add 10 cm3 of hot water. To this add 30

cm3 of 20% KOH solution in small portions. When vigorous effervescence subside,

heat the solution till all the aluminium dissolves completely. Filter through a small

plug of glass wool. To this add about 10 cm3 of water and heat the solution to boiling.

Weigh 14g. of oxalic acid and add it in small portions to the hot solution until the

precipitate of hydrated alumina formed first, is just redissolved on continued boiling.

Neutralise the solution by adding NH4OH solution drop by drop. (Test with litmus

paper).

Filter the neutralised solution and cool the filtrate at room temperature. To this

add 50 cm3 ethanol and cool in ice-cold water. Wash the crystals on the filter paper

with 50% ethanol. Dry it in air at room temperature. Weigh the product, on rough

balance.

Calculate theoretical and practical percentage yield of the product. Present your

results as follows :

Results :








Preparation of Tris (ethylenediammine) nickel (II) thiosulphate,

[Ni (en)3] S

2O

3.

Dissolve 5g of nickel nitrate and 6 cm3 of ethylenediamine, together in about

25cm3 of distilled water by vigorous stirring.

In another beaker, dissolve 5 g of sodium thiosulphate in about 50 cm3 of

distilled water. Boil the two solutions and then add thiosulphate solution to nickel

nitrate solution, 1cm3 at a time, with continuous stirring. Boil the resulting solution

for a minute or so, stir vigorously and allow it to cool on an asbestos sheet. Collect

the violet coloured product on Buchner funnel by suction. Wash the product with cold

water for 2-3 times followed by a little ethanol.

Dry the product at about 1000C (373 K).

Weigh the product on a rough balance. Calculate theoretical and practical

percentage yield of the product. Present your results as follows :

Results :







Time : 6 ½ hours) (Marks : 15)

Preparation of Ammonium diammine tetrathiocyanato chromate (III)

NH4 [Cr (CNS)

4 (NH

3)2], H

2O (Reineck’s Salt)

Fuse 10g of ammonium thiocyanate at 1500C (423 K) in an evaporating dish. Stir

the fused mass. To this melt add 2 g of crushed powder of ammonium dichromate, in

small lots (200 mg), with constant stirring. Violent reaction occurs with evolution of

NH3. Heat the dish carefully until brisk effervescence stop. Cool the purple coloured

melt and allow it to solidify.

Powder the solid mass. Transfer it to a beaker and dissolve out unreacted

Ammonium dichromate by shaking the impure product with 20 cm3 of ice cold water.

Filter the solution by suction. Wash the solid with alcohol followed by cold distilled

water.

Recrystallization :

Dissolve the crude product in about 25cm3 of hot distilled water at about 700C

(343K). Filter the solution while hot. Cool the filtrate in ice-bath and allow the Reineck’s

salt to recrystallize as a glistening red solid.

Filter the solution by suction, dry the product in sunlight and record its yield.

Calculate theoretical and practical percentage yield of the complex. Present your results

as follows :

Results :

(1) Practical yield of the product = .................... g. = ............. x 10-3 kg






(Time : 6 ½ hours) (Marks : 15)

Preparation of Chloropentammine Cobalt (III) Chloride

[Co (NH3)5 Cl]Cl

2

Dissolve 10 gm of ammonium carbonate in 50 cm3 of distilled water. Add about

25 cm3 ammonia in it.

Dissolve 5 gm Cobalt chloride in 50 cm3 distilled water. Add ammonium carbonate

soln. to cobalt chloride soln. with constant stirring Cool it. Add 1 gm ammonium chloride

in evaporating dish. Pour reaction mixture on it. Heat gently. Red crystals will develop.

Add 6M HCl in it. CO2 expel out. Neutralise by NH

3. Heat the mixture. Add 25cm3 conc.

HCl. Heat it. Cool it in ice bath. Add 10cm3 ethanol. Dry the product. Weigh it on rough

balance.

Calculate theoretical and practical percentage yield. Present your results as follows :

Results :

i) Yield of the product = .................... gm. = ............. x 10-3 kg

ii) Theoretical yield of product = ....................... gm. = ............. x 10-3 kg

iii) Practical percentage yield of the product = ...................... %





Preparation of hexammine nickel (II) chloride

[Ni (NH3)6] Cl

2

Dissolve 5 gm Nickel chloride in 15 cm3 warm water. Add 20 cm3 liquor ammonia

in it with constant stirring until green precipitate of Nickel hydroxide dissolves. Cool

the solution in ice bath. Crystals of hexammine nickel chloride separates out. Filter

the product on Buchner fannel. Wash it with ammonia. Solution Dry the product and

weigh it on a rough balance.

Calculate theoretical and practical percentage yield Present your results as follows

:

Results :

1) Yield of the product = ...................... gm = ............. x 10-3 kg

2) Theoretical yield of product = ................. gm = ............. x 10-3 kg

3) Practical percentage yield of the product =......................%





Preparation of tris (thiourea) Copper (I) sulphate

[Cu (tu)3 ]2

SO4,

2H2O

Dissolve 8 gram thiourea in 50 ml warm distilled water and 8 gram copper

sulphate in 50 cm3 warm distilled water. Cool both the solutions at room temperature.

Add copper sulphate solution to thiourea solution with constant stirring. Cool the

mixture in ice cold water. Yellowish oily layer adheres to the wall of the flask. Shake

oily layer with 4 gm thiourea in 40 cm3 of water until crystallisation is complete.

Filter on Buchner funnel and wash with cold water Dry the sample and weigh on

a rough balance.

Calculate theoretical and practical percentage yield. Present your result as follows:

Results :

1) Yield of the product = .................... gm. = ............. x 10-3 kg

2) Theoretical yield of product = ........................... gm. = ............. x 10-3 kg

3) Practical percentage yield of the product = ........................................%

(Titrimetry - V1) : I-11




Percentage Purity of Ferrous Ammonium Sulphate

In a capsule marked (V) bearing your Table number, you are given a sample of

ferrous ammonium sulphate. Determine percentage purity of this sample by redox

titration using 0.1 N K2 Cr

2 O

7 solution.

Instructions :

1) Weigh accurately about, but not exactly, 5.0 g of the given sample (4.800 to

5.200 g).

2) Dissolve the sample in distilled water, add about 10.0 cm3 dilute H2SO

4 and

dilute it to 250cm3 in a measuring flask.

3) Titrate 25cm3 of the diluted solution against 0.1 N K2 Cr

2 O

7 solution using

internal indicator.

4) Determine the percentage purity of the sample using the following relation :

1.0 cm3 0.1 N K2Cr

2O

7 ≡ 0.0392 g FeSO

4 . (NH

4)2 SO

4 . 6H

2O

Present your results as follows

Results :

1) 25 cm3 diluted solution ≡ ............... cm3 0.1 N K2 Cr

2 O

7

2) Volume equivalent to 0.5 g sample ≡ ............... cm3 of 0.1 N K2 Cr

2 O

7

3) Percentage purity of the given sample ≡ ...................%





Percentage Purity of Tetrammine copper (II) sulphate


Tetrammine copper (II) sulphate. Determine percentage purity of this sample by redox

titration using N/20

Na2 S

2 O

3 . 5H

2 O solution.

Instructions :


1.700 g).

2) Dissolve the sample in distilled water, add about 10.0 cm3 dilute acetic acid.

Dilute the solution to 250 cm3 in a measuring flask.

3) Titrate 25cm3 of the diluted solution against N/20

Na2 S

2 O

3 . 5H

2 O solution.

4) Determine the percentage purity of the given sample using the following relation:

1.0 cm3 N/20

Na2 S

2 O

3 . 5H

2 O solution. ≡ 0.01229 g complex

Present your results as follows

Results :

1) 25 cm3 diluted solution ≡ ............... cm3 N/20

Na2 S

2 O

3 . 5H

2 O

2) Volume equivalent to 0.150 g sample ≡ ............. cm3 N/20

Na2 S

2 O

3 . 5H

2 O

3) Percentage purity of the given sample ≡ ................... %





Percentage Purity of Potassium trioxalatoaluminate (III)


Potassium trioxalatoaluminate (III). Determine percentage purity of the sample by redox

titration using 0.1 N KMnO4 solution.

Instructions :


1.650 g).

2) Dissolve the sample in distilled water, and add about 20 cm3 dilute H2SO

4. Dilute

the solution to 250 cm3 in a measuring flask.

3) Titrate 25cm3 of the diluted solution against 0.1 N KMnO4 solution.

4) Calculate theoretical and practical percentage of oxalato group in the sample

and hence determine the percentage purity of the given sample using the

following relation :

1.0 cm3 0.1 N KMnO4 ≡ 0.0044 g oxalato group.

Present your results as follows ;

Results :

1) 25 cm3 diluted solution ≡ ............... cm3 0.1 N KMnO4

2) Volume equivalent to 0.145 g sample ≡ ............. cm3 0.1 N KMnO4

3) Percentage of oxalato group in the given sample ≡ ...................%





(Time : 6 ½ hours) (New Course) (Marks : 15)

Percentage Purity of Potassium trioxalatoferrate (III)


Potassium trioxalatoferrate (III). Determine percentage purity of the sample by redox

titration using 0.1 N K2 Cr

2 O

7 solution.

Instructions :


6.500 g).

2) Transfer the sample to a beaker alongwith about 20 cm3 distilled water. Add

about 20 cm3 conc. H2SO

4 carefully and dissolve the sample by gentle warming.

Add about 50 cm3 distilled water, boil to get clear solution of the sample. Cool

and dilute the solution to 250 cm3 in a measuring flask.

3) Titrate 25cm3 of the diluted solution after reduction by SnCl2 against

0.1N K2 Cr

2 O

7 solution using internal indicator.

4) Calculate the precentage purity of the sample using the following relation :

1.0 cm3 0.1 N K2 Cr

2 O

7 ≡ 0.0491 g of the chelate

Present your results as follows :

Results :

1) 25 cm3 diluted solution ≡ ............... cm3 0.1 N K2 Cr

2 O

7

2) Volume equivalent to 0.630 gm sample ≡ ............. cm3 0.1 N K2 Cr

2 O

7






Magnesium From Talcum Powder

In a capsule marked (V) bearing your Table number, you are given a commercial

sample of Talcum Powder. Determine percentage of Magnesium by complexometric titration

using 0.01 M EDTA solution.

Instructions :


1.800 g).

2) Transfer the sample to a beaker alongwith about 10 cm3 distilled water. Add

about 10.0 cm3 conc. HCl and boil for about 5 minutes. Cool and add about 50

cm3 distilled water. Filter through Whatman filter paper. Dilute the filtrate and

washings to 250 cm3 in a measuring flask.

3) Pipette out 25.0 cm3 of this solution. Neutralise free acid with ammonia. Test by

litmus. Add 5.0 cm3 buffer and titrate against 0.01M EDTA using Erio chrome

black T indictor.

4) Determine percentage of magnesium in the sample by using the relation :

1.0 cm3 0.01 M EDTA ≡ 0.0002431 g of Mg


Results :

1) 25.0 cm3 diluted solution ≡ ............... cm3 0.01 M EDTA

2) Volume equivalent to 0.150 g sample ≡ ............. cm3 0.01 M EDTA

3) Percentage of Magnesium in the given sample ≡ ...................%





Aluminium From Potash Alum

In a 250 cm3 measuring flask marked (V) bearing your Table number, you are

given a solution of Potash alum. Determine the amount of aluminium by

complexometric (indirect) titration using standard solution of Zn ↔ SO4 . 7 H

2 ↔O and

EDTA.

Instructions :

1) Dilute the given solution to 250 cm3 using distilled water.

2) Blank titration reading : 25 cm3 approx. 0.01 M EDTA + 5.0 cm3 (1 : 1)

ammonia solution + Erio T indicator. Titrate against 0.01 M Zn SO4 . 7H

2O

solution.

3) Back titration reading : 25cm3 diluted potash alum solution + 25 cm3

approx. 0.01 M EDTA + 5.0 cm3 (1 : 1) ammonia solution, boil and cool. Add

5.0 cm3 (1 : 1) ammonia and Erio T. Titrate against 0.01M Zn SO4 . 7 H

2 O

solution.

4) Determine the amounts of aluminium and potash alum in the given sample

by using the relations :

1.0 cm3 (difference between Blank and Back readings) of 0.01M ZnSO4 . 7 H

2 O

≡ 0.0002698 g Al

≡ 0.004744 g Potash Alum


Results :

1) Blank titration reading ≡ .................. cm3 0.01 M ZnSO4 . 7H

2 O

2) Back titration reading ≡ .............. cm3 0.01 M ZnSO4 . 7H

2 O

3) Difference between blank and back titration readings ≡ .............. cm3 0.01M ZnSO4

. 7H2 O

4) Quantity of Al in the given sample ≡ ................ g ≡ ............. x 10-3 kg

5) Quantity of potash alum in the given sample ≡ .................. g ≡ ............. x 10-3 kg





Titrable Acidity of Milk / Lassi

Determine titrable acidity of the supplied sample of milk/lassi by acid-base

titration.

Instructions :

1) Prepare 100 cm3 of 0.1 N oxalic acid solution.

2) Standardise supplied NaOH solution using 10cm3 of 0.1 N oxalic acid.

3) Take two different volumes of milk / lassi by common burette (W g) :

10 15 20 25 30 35 cm3 of milk / lassi.

Titrate the sample against supplied NaOH solution using phenolphthalein

indicator. (Assume the density of milk / lassi = 1.0)

4) Calculate the normality of NaOH.

5) Calculate the titrable acidity of milk / lassi in terms of percentage of lactic acid

using the relation :

1000 cm3 1.0 N NaOH ≡ 90.0 g lactic acid

∴ Titrable acidity ≡ _________

percent lactic acid

where V = titration reading

N1 = Normality of NaOH

W = mass of milk / lassi in g

≡ (Volume of milk / lassi taken)


Results :

1) 10 cm3 0.1N Oxalic acid ≡ ................. cm3 supplied NaOH

2) Titrable acidity of milk / lassi for : Set I ≡ .................. % lactic acid

Set II ≡ ................ % lactic acid.

9 × V × N1

W





Percentage Purity of Boric acid

In a Capsul marked (v) bearing your table number, you are given a Sample of

boric acid. Determine the percentage purity of the Sample by acid-base titration

using NaOH solution.

Instructions :

1. Prepare 100 ml. 0.1 N oxalic acid solution and standardise supplied NaOH

solution using 10 cm3 of 0.1 N oxalic acid.

2. Weigh accurately but not exactly 0.250 gm. Of the given Sample (0.200 to

0.300 gm.)

3. Dissolve the sample in distilled water and dilute to 100 cm3 in a measuring

flask.

4. Pipette out 10 cm3 diluted solution. Add 10 ml, 10% glucose solution in to it

and titrate against 0.1 N NaOH solution using Phenolphthalein indicator.

5. Determine the percentage purity of sample using following relation.

1 cm3 of 0.1 N NaOH ≡ 0.006184 gm H3BO

3


Results :

1) 10 cm3 diluted solution = ................................. cm3 0.1 N NaOH

2) Volume equivalent to 0.0250 gm sample = ................ cm3 of NaOH

3) Percentage purity of the given sample = .....................................%





Estimation of Sodium by Ion-Exchange Method

In a 100 cm3 measuring flask marked (V) bearing your Table number you are

given a solution of common salt. Determine the amount of sodium and sodium

chloride using Cation Exchange Resin column by acid-base titration.

Instructions :

1) Wash the cation exchange column using about 50 cm3 distilled water and

reject the washings.

2) Dilute the given solution to 100 cm3 using distilled water and shake well.

Pipette out 10 cm3 of this solution and transfer on the resin column.

3) Wash the resin column by using about 100 cm3 distilled water and collect the

effluent in a 250 cm3 measuring flask by adjusting the rate 4 to 5 cm3 per

minute.

4) Dilute the effluent solution to 250 cm3 using distilled water and titrate 25 cm3 of

this solution against __

NaOH solution.

5) Calculate the amounts of sodium and sodium chloride present in the given

solution by using the relation :

1.0 cm3 ___ NaOH ≡ 0.00115 g sodium

≡ 0.002921 g sodium chloride


Results :

1) 25 cm3 diluted effluent solution ≡ ................ cm3 ___

NaOH

2) Quantity of sodium in the given solution ≡ .................. g = ............. x 10-3 kg

3) Quantity of sodium chloride in the given solution ≡ ................... g = ............. x 10-3 kg

N

20

N

20

N

20

(Titrimetry - V10/11) : I-20




Estimation of Magnesium / Zinc by Ion-Exchange Method

In a 100 cm3 measuring flask marked (V) bearing your Table number, you are

given a mixture containing Mg (II) and Zn (II). Determine the amount of Mg (II)/Zn (II)

using Anion Exchange Resin Column by complexometric titration.

Instructions : Part-I (Estimation of Mg (II)]

1) Wash the anion-exchange column, using about 50cm3 dilute HCl and reject the

washings.

2) Then wash with about 50cm3 with distilled water to remove excess of acid.

3) Dilute the given solution to 100 cm3 using distilled water and shake well. Pipette out

10cm3 of this solution and transfer it to the resin column.

4) Wash the resin column by about 80 cm3 of dilute HCl and collect the effluent in a 250

cm3 measuring flask by adjusting the rate 4 to 5 cm3 per minute.

5) Dilute the effluent solution containing Mg (II) to 250 cm3 using distilled water.

Pipette out 25 cm3 of this solution, neutralise by (1 : 1) ammonia or by alkali NaOH

Solution, test by litmus paper. Add 5.0 cm3 buffer and Erio T indicator. Titrate this

solution against 0.01 M EDTA solution.

6) Calculate the amount of Mg (II) in the given solution using the relation :

1.0 cm3 0.01 M EDTA ≡ 0.0002431 g Mg

Instructions : Part-II [Estimation of Zn (II)]

7) Reject the effluent collected in Part-I

8) Wash the resin column, free from Mg (II), by about 80 cm3 0.25 N HNO3 and collect

the effluet in another 250 cm3 measuring flask by adjusting the rate 4 to 5 cm3 per

minute.

9) Dilute the effluent solution containing Zn (II) to 250 cm3 using distilled water.

Pipette out 25 cm3 of this solution, neutralise by (1 : 1) ammonia, or by alkali NaOH

solution test by litmus paper. Add 5.0 cm3 buffer and Erio T indicator. Titrate this

solution against 0.1 µ M EDTA solution.

10) Calculate the amount of Zn (II) present in the given solution by using the relation :

1.0 cm3 0.01 M EDTA ≡ 0.0006538 g Zn (II). Present your results as follows :

Results :

1) 25 cm3 diluted effluent solution containing Mg (II) / Zn (II) ≡ ............. cm3 0.01 M EDTA

2) Quantity of Mg (II) / Zn (II) in the given solution ≡ ................. g. ≡ ............. x 10-3 kg

P-1 (General) SHIVAJI UNIVERSITY, KOLHAPUR Schedule/Practical Exam 2015... · P-3 SHIVAJI...

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Transcript of P-1 (General) SHIVAJI UNIVERSITY, KOLHAPUR Schedule/Practical Exam 2015... · P-3 SHIVAJI...