INTERNATIONAL INDIAN SCHOOL, RIYADH WORKSHEET …4. the acid strength decreases in the order...

of 22

INTERNATIONAL INDIAN SCHOOL, RIYADH

WORKSHEET (2020-2021)

GRADE - XII – CHEMISTRY - SECOND TERM

UNIT 2 SOLUTIONS

WORKSHEET 1

1. Give an example of ‘liquid in solid’ type solution.

2. Which type of solid solution will result by mixing two solid components with large

difference in the sizes of their molecules?

3. What is meant by semimolar and decimolar solutions?

4. What will be the mole fraction of water in C2H5OH solution containing equal

number of moles of water and C2H5OH?

5. Which of the following is a dimensionless quantity : molarity, molality or mole

fraction?

6. 10 gm glucose is dissolved in 400 gm. of solution. Calculate percentage

concentration of the solution.

7. Gases tend to be less soluble in liquids as the temperature is raised. Why?

8. State the conditions which must be satisfied if an ideal solution is to be formed. 9. A

mixture of chlorobenzene and bromobenzene forms nearly but a mixture of

chloroform and acetone does not. Why?

9. 9.How is the concentration of a solute present in trace amount in a solution

expressed?

10. Which aqueous solution has higher concentration 1 molar or 1 molal solution of the

same solute? Give reason.

11. N2 and O2 gases have KH values 76.48 Kbar and 34.86 kbar respectively at

293 K temperature. Which one of these will have more solubility in water?

12. Under what condition molality and molarity of a solution are identical.

Explain with suitable reason.

of 22

13. Addition of HgI2 to KI (aq.) shows decrease in vapour pressure. Why?

14. What will happen to the boiling point of the solution on mixing two miscible liquids

showing negative deviation from Raoult’s law.

15. Liquid ‘Y’ has higher Vapour pressure than liquid ‘X’, which of them will have

higher boiling point?

16. When 50 mL of ethanol and 50 mL of water are mixed, predict whether the volume

of the solution is equal to, greater than or less than 100 mL. Justify.

17. Which type of deviation is shown by the solution formed by mixing cyclohexane

and ethanol?

18. A and B liquids on mixing produce a warm solution. Which type of deviation from

Raoult’s law is there?

19. Define cryoscopic constant (molal freezing point depression constant.)

20. Mention the unit of ebulioscopic constant (molal boiling point

Elevation constant.)

21. If kf for water is 1.86 K kg mol–1. What is the freezing point of 0.1 molalsolution

of a substance which undergoes no dissociation or association of solute.

22. Name the component that separate first when salt solution is frozen.

23. What is reverse osmosis? Give one large scale use of it.

24. What is the maximum value of Van’t Hoff factor for Na2SO4 . 10H2O?

WORKSHEET 2

1. (a) What are ideal solutions? Write two examples.

(b) Calculate the osmoic pressure in pascals exerted by a solution prepared by

dissolving 1.0g of polymer of mol. mass 185000 in 450 ml of water at 37°C.

2. (a) Describe a method of determining molar mass of a non-volatile solute from

vapour pressure lowering.

(b) How much urea (mol. mass 60 g mol–1) must be dissolved in 50g of water so

that the vapour pressure at the room temperature is reduced by 25%? Also calculate the

molality of the solution obtained.

3. (a) Why is the freezing point depression considered as a colligative property?

of 22

(b) The cryoscopic constant of water is 1.86 Km–1. Comment on this statement. (c)

Calculate the amount of ice that will separate out on cooling solution containing 50 g

of ethylene glycol in 200 g H2O to –9.3°C

.(Kf for water = 1.86 K kg mol–1)

4. (a) Define osmotic pressure.

(b) Why osmotic pressure is preferred over other colligative properties for the

determination of molecular masses of macromolecules?

(c) What is the molar concentration of particles in human blood if the osmotic

pressure is 7.2 atm at normal body temperature of 37°C?

WORKSHEET 3

1.Spreading of common salts on the icy roads in a practical applications on depression in

freezing point.Can we use CaCl2 in place of NaCl? Why?

2. What type of azeotrope is formed on mixing nitric acid and water?

3. When 30 ml gram ethanol and 30 ml gram of water are mixed,the volume of resulting

solution is more than 60 ml.Give reason.

4. Aquatic species feel more comfortable during winter then summer season. Why?

5.Vendors selling aerated drinks bottles are adviced to keep them immersed inside cold

water during summer. Why?

6. If α is the degree of dissociation of Na2SO4 then write the vant hoff factor used for

calculating the molecular mass.

7. If 6.023 𝑥 10 mole cubes of urea are present in 100 ml of its solution, then what is

the concentration of urea solution?

8. Why a person suffering from high blood pressure is advised to take minimum

quantity of common salt?

9. Which colligative property is preffered for the molar mass determination of macro

molecules.Why?

10. 0.004 M solution of Na2So4 is isotonic with 0.01M solution of glucose at a given

temperature. What is the apparent degree of dissociation of Na2SO4

of 22

UNIT 3 ELECTROCHEMISTRY

WORKSHEET 1

1. What is a galvanic cell?

2. Give the cell representation for Daniell Cell.

3. Mention the purpose of salt-bridge placed between two half-cells of a galvanic cell?

4. Give the condition for Daniel Cell in which there is no flow of electrons or current or we

can conclude that there is no chemical reaction.

5. How is electrode potential different from cell potential?

6. Can you store zinc sulphate solution in a copper container? Give suitable reason.

7. How does electrochemical series help us in predicting whether a redox reactions is

feasible in a given direction or not?

8 As per electrochemical series and on the basis of E° values, identify the following :

(a) Gas which has highest tendency for reduction.

(b) Weakest oxidising ion.

9. List the two factors that influence the value of cell potential of a galvaniccell. 10.Write

the cell reaction in a lead storage battery,H2-O2 fuel cell

WORKSHEET 2

1.. Calculate the equilibrium constant for the reaction at 25°C.

Cu(s) + 2Ag+ (aq) ------ Cu2+ (aq) + 2Ag (s)

The standard cell potential for the reaction at 25°C is 0.46V.

2.Conductivity of two electrolytic solutions of 0.1 M concentration of the substances A and

B are 9.2 × 10–3 and 4.7 × 10–4 S cm–1, which one of these offer less resistance for the

flow of current and which one is a stronger electrolyte?

3.What is the no of electrons in 1 coloumb of charge?

4.Which solution will allow greater conductance of electricity, 1M NaCl at 293k or 1M NaCl

At 323K and why?

5.Why is the equilibrium const. K related to only 𝑥 cell and not to Ecell ?

6.What is the sign of G for an electrolytic cell?

7.Rusting of iron is quicker in saline water than in ordinary water why ?

of 22

8.Can a nickel spatula be used to stir a solution of copper sulphate ?. Justify your answer.

[𝑥 𝑥𝑥 /Ni = -0.25V & 𝑥 𝑥𝑥 /Cu = 0.34V ]

9.What would happen if the protective tin coating over an iron bucket is broken in some

places. ?

10.Which out of 0.1M HCL and 0.1M NaCl, do you expect to have greater λ value and why?

11.What will be the E.M.F, when the cell reaches equilibrium.?

12.Which will have greater molar conductivity? Solution containing 1 mole KCl in 200 cc.or

1 mol g KCL in 500cc.

UNIT 7 P BLOCK

1.Draw structures of: H3PO3, XeOF4, SF4 ,XeF4 ,

BrF3 ,H3PO4, H2S2O8 ,H2S2O7, HClO4, HClO3,XeF6 .

2.Write one chemical reaction each to show that con: H2SO4 can be an oxidizing agent .

3.Write chemical equation involved in the preparation of the following.(i) XeF4

(ii)H3PO3

4.Account for the following

1. Thermal stability of water is much higher than that of H2S

2. White phosphorus is more reactive than red phosphorus

3. In solid state PCl5 behaves as an ionic species

4. the acid strength decreases in the order HF˂HCl˂HBr˂ HI

5. Ammonia is a stronger base than phosphine

6. The +5 oxidation state of Bi is less stable than its +3 state.

7. SF6 is not easily hydrolysed whereas SF4 is readily hydrolysed

8. Bond dissociation enthalpy F2 is leser than that of Chlorine.

9. Nitrogen does not form pentahalide

10.Fluorine is a stronger oxidizing agent than chlorine.

5.Complete the equations:

1. Ca3P2 + H2O

2. Cu 2+ aq + NH3

3. XeF6 + H2O

4. NaCl + MnO2 + H2SO4

5. NaI + Cl2

6. PCl3 +SO2Cl2

of 22

6.Which is the most stable thermodynamic form of sulphur?

7.Describe contact process for the manufacture of H2SO4

8.Write chemical equation:

(i) Chlorine treated with a hot concentrated solution of NaOH (ii)Orthophosphoric acid is

heated.

UNIT 10

HALOLKANES AND HALOARENES

1.Write the structure of following halogen compounds

(i) D D T

(ii) Freon – 12

(iii)1–Bromo 4-sec-butyl-2-methylbenzene. (iv) p-Bromotoluene. (v) Methylene chloride

(vi) Chloral

2.. Arrange the following in the increasing order of property indicated :

(i) Bromomethane, bromoform, chloromethane, dichloromethane.

(Increasing order of boiling points).

(ii) 1-Chloropropane, isopropyl chloride, 1-chlorobutane

(Increasing order of b.pt.)

(iii) Dichloromethane, chloroform, carbon tetrachloride.

(Increasing order of dipole moment).

(iv) CH3F, CH3Cl, CH3Br, CH3I

(Increasing reactivity towards nucleophilic substitution).

(v) o, m, p-dichlorobenzenes (Increasing order of melting points).

3. Write the difference between

(i) enantiomers and diastereomers

(ii) retention and inversion of configuration.

(iii) electrophilic and nucleophilic substitution reactions.

4. Give a chemical test to distinguish between the following pairs of compounds:

(i) Chlorobenzene and cyclohexylchloride.

(ii) Vinyl chloride and Ethyl chloride.

(iii) n-Propyl bromide and Isopropyl bromide.

5. Which compound in each of the following pairs will react faster in SN2

reaction with OH– and why? (i) CH3Br or CH3I (ii) (CH3)3 CCl or CH3Cl

(iii) C6H5CH2Cl and C6H5C(Cl)C6H5

(iv) CH2 = CH – Cl and CH2 = CH – CH2Cl

of 22

6. Give reasons for the following :

(i) The bond length of C–Cl bond is larger in haloalkanes than that in

haloarenes. (ii) Although alkyl halides are polar in nature but are not soluble in

water. (iii) t-Butyl bromide has lower boiling point than n-butyl bromide. (iv) Haloalkanes react with KCN to form alkyl cyanide as main product while with AgCN alkylisocyanide is the main product. (v) Sulphuric acid is not used in the reaction of alcohol with Kl. (vi) Thionyl chloride is the preferred reagent for converting ethanol to

chloroethane. (vii)Haloalkanes undergo nucleophilic substitution reaction easily but haloarenes

do not undergo nucleophilic substitution under ordinary conditions. (viii) Chlorobenzene on reaction with fuming sulphuric acid gives ortho and

para chlorosulphonic acids. (ix) 2, 4-Dinitro chlorobenzene is much more reactive than

chlorobenzene towards hydrolysis reaction with NaOH.

(x) Grignard reagent should be prepared under anhydrous

UNIT 11

ALCOHOLS,PHENOLS AND ETHERS

1. Write the equations of the following named reactions:a) Hydro boration b)

williamson's synthesis c) cumene phenol process d) Kolbe's reaction e) Riemier

Tiemann reaction

2. Explain Lucas test with suitable examples

3. Distinguish chemically between the following pairs of organic compounds

a) Phenol and methanol b) methanol and ethanol c) propan-1-ol and propan-2-ol

d) pentan-3-ol and 2-Methyl butan 2-ol

4. Account for the following:

a) COH bond angle in alcohol is less than tetrahedral angle of 109.50

b) COC bond angle in ether is more than tetrahedral angle of 109.50

c) Phenol has lower dipole moment than alcohol.

d) Phenol under goes electrophillic substitution at ortho and para position

e) Phenol is more acidic than alcohol.

f) In Williamson’s synthesis sec and tert halide can not be used.

g) para nitro phenol is less steam volatile than ortho nitro phenol.

of 22

h) Presence of nitro group at ortho and para position makes phenol more acidic.

i) Alcohols and phenols have higher boiling point

j) Boiling point of alcohol is higher than its isomeric ether.

k) Cresol is less acidic than phenol.l) In esterification reaction, water is removed as soon

as it isformed

m) Phenol and anisole undergoes bromination reaction even in the absence of halogen

carrier.

n) Methyl phenyl ether reacts with HI to give phenol and methyl iodide and not methanol

and iodo benzene.

o) Methoxy ethane reacts with HI to give methyl iodide and ethanol and not ethyl iodide

and methanol.

p) Tert butyl methyl ether reacts with HI to give tert butyl iodide and methanol and not

not methyl iodide and tert butyl alcohol.

q) Boiling point of butan-1-ol is higher than tert butyl alcohol.

r) In the reaction between acid chloride and alcohol a small amount of pyridine is added.

s) Alcohol behaves as nucleophile as well as electrophile.

5. Carry out the following conversions:

a) Ethanal to ethanol.b) Acetone to propan-2-ol.c) Ethanoic acid to ethanol.

d) Ethene to ethanol.e) Propene to propan-2-ol.f) Methanal to ethanol.

g) Methanal to benzyl alcohol.h) Ethanal to propan-2-ol.i) Acetone to 2-methyl propan-

2-ol.

j) But-1-ene to butan-1-ol.k) But-2-ene to butan-2-ol.l) Chloro benzene to phenol.

m) Aniline to phenol.n) Benzene to phenol.o) Tert butyl alcohol to 2-methyl prop-1ene.

p) Propan-2-ol to acetone.q) Benzyl chloride to benzyl alcohol

r) Ethyl magnesium chloride to propan-1-ols) Cumene to phenol

6. Explain the mechanism of the following reactions:

a) CH2= CH2 + H2O CH3CH2OH

b) CH3CH2OH CH2=CH2+H2O

c) CH3CH2OH CH3CH2OCH2CH3

of 22

UNIT 6 PRINCIPLES OF ISOLATION

WORKSHEET 1

1. Out of C and CO, which is better reducing agent at 673K?

2. What is the principle of Zone refining?

3. Name a metal which can be refined by electrolytic method.

4. Name the metal extracted by Hall-Heroult process.

5. Suggest a condition under which magnesium could reduce alumina.

6. Why the reduction of a metal oxide is easier if the metal formed is in liquid state at the

temperature of reduction?

7 .The reaction, Cr2O3 + 2 Al Al2O3 + 2Cr (∆G0 = – 421 kJ) is thermodynamically

feasible as is apparent from the Gibbs energy value.

Why does it not take place at room temperature?

8. Copper can be extracted by hydrometallurgy but not zinc. Explain why?

9. Write chemical reactions taking place in the extraction of zinc from zincblende.

10. Write two basic requirements for refining of a metal by Mond process and by Van

Arkel Method.

11. Explain the following :

(a) CO2 is a better reducing agent below 710K whereas CO is a better reducing agent

above 710K.

(b) Generally sulphide ores are converted into oxides before reduction.

(c) Silica is added to the sulphide ore of copper in the reverberatory furnace.

WORKSHEET 2

1.How is ‘cast iron’ different from ‘pig iron”?

2. What is the role of cryolite in the metallurgy of aluminium?

3. Out of C and CO, which is a better reducing agent for ZnO ?

4. How can we extract Copper from Low Grade Ores and Scraps

5. Define and differentiate between “minerals” and “ores”.

6. Giving example differentiate between ‘roasting’ and ‘calcination’.

7. Name the processes from which chlorine is obtained as a by-product. What will happen

if an aqueous solution of NaCl is subjected to electrolysis?

of 22

8.Explain Hall Heroult process

9 Describe the extraction of zinc .

10 Outline the principles of refining of metals by the following methods:

(i) Zone refining

(ii) Electrolytic refining

(iii) Vapour phase refining

11 Give one example of a metal which can be refined by

(a) Distillation (b) Liquation (c ) Chromatographic methods

WORKSHEET 3

1.What is the role of graphite rod in the electrometallurgy of aluminium? 1

2. The mixture of compounds A and B is passed through a column of Al2O3 by using

alcohol as eluant. Compound A is eluted in preference to compound B. Which of the

compounds A or B, is more readily adsorbed on the column?

3. Why copper matte is put in silica lined converter? 1

4 What is the role of cryolite in the metallurgy of aluminium? 1

5 The value of ∆fG0 for formation of Cr2O3 is – 540 kJmol−1and that of Al2O3 is – 827

kJmol-1. Is the reduction of Cr2O3 possible with Al?

6 Describe a method for refining nickel.

7 How do we separate two sulphide ores by Froth Floatation Method?

Explain with an example.

8 Which method is used for refining Zr and Ti? Explain with equation. 9 Write the

chemical reactions involved in the extraction of gold by cyanide process. Also give the

role of zinc in the extraction

10.Distinguish between roasting and calcination.

UNIT 12

ALDEHYDE,KETONE AND CARBOXYLIC ACID

1. Write equations for the following named reactions:

a) Nucleophillic addition reaction.b) clemensen reduction.

c) wolf kishner reduction.d) aldol condensation.e) crossed aldol condensation

of 22

f) cannizaro reaction.g) Rosenmund's reduction.h) kolbe's electrolysis

i) Stephen reaction.j) Etard reaction.k) decarboxylation.l) acylation.

m) schotten baumann reaction.n) Friediel craft's acylation.o) esterification.

p) Gattermann- Koch reaction.q) Hell Volhard Zelensky reaction.

2. Explain

a) Fehling's testb) Tollen's reagent test with suitable examples.

3. Distinguish chemically between the following pairs of organic compounds:

a) Methanal and ethanal.b) ethanal and propanone.c) pentan-2-one and pentan3-one.

d) aceto phenone and benzo phenone.e) formic acid and acetic acid.

f) benzoic acid and ethyl benzoate.g) phenol and benzoic acid.h) ethanal and propanal.

i) propanal and diethyl ether.j) benzaldehyde and acetophenone.k) ethanal and

propanone

4. Account for the following:

a) Aldehyde and ketone are polar in nature.

b) Aldehyde and ketones have higher boiling point than hydro carbons of comparable

molar mass.

c) Aldehyde and ketones have lower boiling point than alcohols of comparable molar

mass.

d) Ketone has higher boiling point than aldehyde of comparable molar mass.

e) Oxidation of primary alcohol to aldehyde is carried out using PCC as an oxidizing

agent.

f) Rosenmund's reduction of acid chloride to aldehyde is carried out using quinoline

and sulphur.

g) Aldehyde is more reactive than ketone towards nucleophile.

h) Butanone is less reactive than propanone.

i) 2,2,6-Tri methyl cyclo hexanone is less reactive towards nucleophile than cyclo

hexanone.

j) Para nitro benzaldehyde is more reactive towards nucleophile than benzaldehyde.

k) Para methyl benzaldehyde is less reactive towards nucleophile than benzaldehyde.

of 22

m) Reaction of aldehyde with alcohol to give acetal is carried out in the presence of

HCl(g).

n) Formaldehyde and benzaldehyde undergoes cannizaro reaction and not aldol

condensation.

o) Acetaldehyde undergoes aldol condensation and not cannizaro reaction.

p) Aromatic aldehyde and ketones undergoes electrophillic substitution at meta

position.

q) Carboxylic acid do not show the reactions of aldehyde and ketone though it has

>C=O group.

r) Carboxylic acid has higher boilimg point than aldehyde, ketone and alcohol of

comparable molar mass.

s) In semi carbazide, only one NH2 group is involved in the formation of semi

carbazone.

t) Aldehyde, ketone and carboxylic acid are soluble in water.

u) In oxidation of primary alcohol to carboxylic acid is not carried out using acidified

potassium dichromate.

v) Carboxylic acid is more acidic than alcohol.

w) Carboxylic acid is more acidic than phenol.

x) Acidity of CCl3COOH>CHCl2COOH>CH2ClCOOH>CH3COOH.

y) Acidity of FCH2COOH>ClCH2COOH>BrCH2COOH>I CH2COOH.

z) a chloro propanoic acid is more acidic than ß chloro propanoic acid.

aa) Acetic acid is less acidic than formic acid.

bb) Pure acid halide is prepared by the reaction of carboxylic acid with thionyl

chloride.

cc) Carbon in carbonyl group of aldehyde and ketone acts as Lewis acid(electrophile)

while oxygen acts as Lewis base ( nucleophile). dd) Benzoic acid does not

undergo Friediel craft alkylation reaction.

5. How is a) HCHO b) CH3CHO c) C6H5CHO prepared commercially?

Mention two uses of each.

6. How is a) HCOOHb) CH3COOHc) C6H5COOH prepared commercially?

Mention two uses of each.

of 22

7. Carry out the following conversions:

a) Ethanol to ethanal.b) Methanol to methanal. c) Propan-2-ol to propanone.

d) Methanal toi) ethanol ii) benzyl alcohol.

e) Ethanal toi) propan-2-olii) acetone.

f) Acetone to i) tert butyl alcohol ii) 2-Methyl prop-1-ene.

g) Benzaldehyde toi) a- hydroxy phenyl acetic acidii) 3-phenyl propan-1-ol

iii) 1- phenyl ethanol.iv) benzyl alcohol and sodium

benzoate. v) cinnamaldehyde.

vi) 1,3-Diphenyl prop- 2-en-1-onevii) benzo phenoneviii) m-nitro benzaldehyde ix)

benzal acetophenone.h) Butan-1-ol to butanal.

i) Cyclo hex-2-en-1-ol to cyclo hex-2-en 1-one.j) Pentan-3-en-2-ol to pent-3-en-2one.

k) But-2-ene to ethanall) Para nitro toluene to para nitro benzaldehyde.

m) Ethanal to butan-2-one. n) Ethanal to butane- 1,3- diol. o) Ethanal to but-2enal

p) Ethanal to but-2-enoic acid. q) Ethanal to butan-1-olr) Ethanal to butanoic acid.

s) Propanone to propene. t) Propanal to butanone.u) Ethanal to 2-hydroxy butanal.

v) Benzaldehyde to benzo phenone. w) Benzoic acid to benzaldehyde.

x) Propanoic acid to propenoic acid.y) Benzene to m-nitro aceto phenone.

z) Bromo benzene to 1-phenyl ethanol. aa) Benzoic acid to m- nitro benzoic acid.

bb) Benzoic acid to benzyl amine. cc) Para nitro benzoic acid to para nitro aniline.

dd) Hexanoic acid to hexane nitrle. ee) Hexanoic acid to 1-amino pentane. ff)

Hept-1-ene to heptanal gg) Hept-1-ene to hexanal. hh) Hept-1-ene to

heptanoic acid.ii) Hept-1-ene to hexanoic acid.

jj) Ethene to ethanal. kk) Propene to acetone.ll) 2, 3- dimethyl but-2-ene to acetone.

mm) Ethanal to lactic acid. nn) Ethanal to ethane. oo) Ethanal to Ethanoic acid.

pp) Acetone to 4-hydroxy-4-methyl pentan-2-one. qq) Benzaldehyde to benzyl alcohol

and sodium benzoate. rr) Methanal to methanol and sodium methanoate. ss) Toluene to

benzaldehyde. tt) Ethyl benzene to benzoic acid.uu) But-2-ene to ethanoic acid.

of 22

v v) Ethane nitrle to ethanoic acid. ww) Methyl magnesium bromide to ethanoic acid.

xx) Para methyl aceto phenone to benzene-1,4- dicarboxylic acid.

yy) Cyclo hexene to hexane-1,6-dicarboxylic acid. zz) Ethanoic acid to ethanol.

aaa) Propanoic acid to a- chloro propanoic acid. bbb) Methanol to Ethanoic acid.

g) Benzene to p- nitro benzoic acid.

h) Benzene to p- nitro benzaldehyde.

i) Benzene to phenyl acetic acid.

j) Ethanoyl chloride to propanone.

k) Benzene to benzaldehyde

l) Ethane nitrile to

i)ethanal ii)

propanal

w) cyclo hexane to Hexane-1,6-dicarboxylic acid.

x) Benzene-1,4-dicarboxylic acid to pthalimide

9. An organic compound A(C8H8O) gives orange red precipitate with 2,4-DNP reagent.

It responds to iodoform test. It does not respond to Tollen’s reagent test. It does not

decolorise bromine water. A on oxidation using CrO3 give B. Identify the compounds

and write thw equations of the reactions involved.

10. An organic compound C9H10O forms 2,4-DNP derivative, reduces Tollen’s reagent

and Undergoes cannizaro reaction. On vigorous oxidation it gives Benzene-1,2-

dicarboxylic acid. Identify the compound.

11. An organic compound contain 69.77% C and 11.63% H and the remaining O.

Molecular mass of the compound is 86 u. It does not reduce Tollen’s reagent, gives

positive iodoform test and respond to sodium bisulphate test. On oxidation it gives

acetic acid and propanoic acid. Give the structure of the organic compound.

12. Arrange the following in the increasing order of property mentioned:

a) Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl tert-butyl ketone(

reactivity with HCN)

b) 2-Bromo butanoic acid, 3-Bromo butanoic acid, Butanoic acid, 3-Methyl

propanoic acid (acid strength)

c) Benzoic acid, 4-Nitro benzoic acid, 3,4-Dinitro benzoic acid, 4-Methoxy

benzoic acid (acid strength)

of 22

d) Ethanal, Propanal, Propanone, Butanone( increasing order of reactivity

towards nucleophile)

e) Benzaldehyde, p-Tolualdehyde, p-Nitro benzaldehyde,

Acetophenone(increasing order of reactivity towards nucleophile)

f) Butanal, Butanol, Ethoxy ethane and Butane (increasing order of boilimg

point)

13. Complete each synthesis by giving missing starting material, reactant or product.

c) C6H5CHO + NH2CONHNH2

d) C6H5CHO + CH3CH2CHO

14. Which acid of each pair would you expect to be stronger?

a) Ethanoicacid and fluoro ethanoic acid

b) Fluoro ethanoic acid and chloro ethanoic acid

c) 4- Fluoro butanoic acid and 3-Fluoro butanoic acid

d) p-Trifluoro benzoic acid and p- Methyl benzoic acid.

15. Arrange the following in the increasing order of boiling point: Ethanal, Ethanol,

Ethoxy ethane and Propane

16. Predict the product formed when cyclohexanecarbaldehyde reacts with

a) PhMgBr+H3O+

b) Tollens’reagent

c) Semicarbazide and weak acid

of 22

d) excess ethanol and acid.

e) Zinc amalgam and dilute HCl

17. Give the products of the following reactions:

c) RCH=CHO + NH2CONHNH2

d) C6H5COCH3 + C2H55NH2

f) (C6H5CH2)2Cd + 2 CH3COCl

UNIT 8 D AND F BLOCK ELEMENTS

Worksheet 1

Account for the following:

1. Zn, Cd and Hg are not considered as transition metals.

2. Cu,Ag &Au are considered as transition metal though it has 3d10 configuration.

3. Zn, Cd and Hg are volatile and Hg is a liquid metal.

4. Transition metals have high enthalpy of atomisation.

5. 4d and 5d elements have higher enthalpy of atomisation than 3d elements.

6. Density of 3d elements increases from Sc to Ni.

7. Atomic and ionic radii generally decrease along the period.

8. Zr and Hf have similar size.

of 22

9. Transition metals do not show regular variation of ionisation enthalpies.

10. 5d elements have higher ionisation enthalpy than 3d and 4d elements.

11. Generally first ionisation enthalpy increases along the period.

12. Cr &Cu has higher second ionisation enthalpy (Cr=24,Cu=29)

13. Mn &Zn has higher 3rd ionisation enthalpy (Mn=25 Zn=30) 14. Cu, Ni and Zn normally

do not exhibit oxidation state higher than +2.

15. Transition metals show variable oxidation state.

16. Transition metals do not show regular variation of E0 values.

17. E0 Mn3+/ Mn2+ have higher +ve value than E0 Cr3+ / Cr2+.(Cr=24 Mn=25).

18. E0 Zn2+ / Zn has higher - value. ( Zn=30).

19. Transition metals form complexes easily.

20. Transition metals act as catalysts.

21. Transition metal compounds are paramagnetic.

22. Sc3+,Cu+ and Zn2+ are diamagnetic .Sc=21 Cu=29 Zn=30).

23. Oxidation state of transition metals increases by one unit.

24. E0 Ni2+ / Ni has higher - ve value.

25. Transition metal compounds are coloured.

26. Sc3+,Cu+ and Zn2+ are colourless .[Sc=21 Cu=29 Zn=30].

27. Transition metals form interstitial compounds easily.

28. Transition metals form alloys easily.

29. Higher oxides of transition metals are acidic.

30. Enthalpy of atomization of transition metals reaches a maximum in the middle of each

series

31. Lanthanoid ions are coloured and paramagnetic.

32. La3+ and Lu3+ are colourless and diamagnetic. (La=57 Lu=71).

33. Ln are paramagnetic.

of 22

34. La3+ is diamagnetic.

35. Ce is stable in +4 oxidation state. E0 Ce4+ / Ce3+ has higher positive value.

36. Eu2+ is a good reducing agent.(Eu=63).

37. Ce4+ is a good oxidising agent .

38. Yb2+ is stable. It acts as a reducing agent. (Yb=70).

39. In lanthanoid hydroxide M(OH)3 basic character decreases with increase in atomic

number.

40. Actinoids show greater range of oxidation state than lanthanoids.

41. Actinoid contraction is greater than lanthanoid contraction.

42. Ionisation enthalpies of early actinoids are lesser than that of early lanthanoids.

43. In the d4 species Mn3+ is an oxidising agent where as Cr2+ is a reducing agent

44. Co(II) is stable in aqueous solution but get oxidised in the presence of complexing

agents.

45. d1 configuration is unstable in transition metals.

46. Transition metals exhibit higher oxidation state in oxides and flourides.

47. Zn has lowest enthalpy of atomisation.

48. First ionization enthalpy of Cr is lower while Zn is higher.(Cr=24, Zn=30)

49. Zn has lower second ionization enthalpy.

50. Number of oxidation states at the extreme ends of 3d transition metals are very few.

51. Transition metals in higher oxidation states are more stabilized in oxides than in

fluorides.

52. E0 Cu2+ / Cu is positive.

53. E0 Sc3+ / Sc2+ has lower value (Sc=21)

54. E0 Zn3+ / Zn2+ have higher positive value.

55. E0 Fe3+ / Fe2+ has comparatively lower positive value than E0 Mn3+ / Mn2+ (Mn=25,

Fe=26)

56. E0 V3+ / V2+ have lower negative value (V=23)

of 22

57. Cu2+ (aq) is more stable than Cu+ (aq) despite the d10 configuration of Cu+

58. Highest fluoride of Mn is MnF4 while highest oxide is Mn2O7.

59. Oxidising power of Oxides VO2+< Cr2O72- <MnO4-

60. KMnO4 titration is not carried out using HCl as acid medium.

61. Third ionization enthalpy of La, Gd and Lu are abnormally low( La=57, Gd=64, Lu=71)

62. 5f electrons can take part in bonding to a greater extent than 4f electron though both

have similar angular wave function.

63. Highest oxidation state is exhibited by oxoanion in transition metals.

64. Generally negative value of E0 M2+ / M decreases across the series of 3d elements.

65. It is unsatisfactory to review the chemistry of actinoids in terms of oxidation state.

66. Lower oxides of transition metal are basic while higher oxides are acidic.

67. Sc exhibits only one oxidation state.

68. Cr2+ is stronger reducing agent than Fe2+

69. Mo(VI) and W(VI) are more stable than Cr(VI)

70. There is a greater horizontal similarity in the transition metals than in the main group

elements.

71. Nickel (II) does not form low spin octahedral complexes.

72. Transition elements form pi complexes.

73. There is more frequent metal-metal bonding in 4d and 5d transition elements.

Worksheet 2

1. What is lanthonoid contraction? What is the reason for lanthonoid contraction?

Mention the consequences of lanthonoid contraction.

2. What is mischmetal? Mention two uses of mischmetal.

3. How is a) KMnO4 prepared from pyrolusite ore?

b) K2Cr2O7 prepared from chromite ore?

4 . Write the ionic equations of the reactions involved when acidified KMnO4 is treated with

a) FAS solution b) oxalic acid solution c) hydrogen sulphide d) KI solution e) Sn2+solution

f) SO32- g) NO2-h) SO2

of 22

5. Write the ionic equation of the reaction involved when alkaline KMnO4 is reacted with

a) KI solution. b) S2O32-

6. Write the ionic equation of the reaction involved when acidified K2Cr2O7 reacts with

a) Sn2+ solution b) SO2 c) hydrogen sulphided) Fe2+

7. What is the effect of PH on chromate and dichromate solutions?

8. Compare the chemistry of lanthonoids and actinoids with reference to

a) electronic configuration b) oxidation state c) ionization enthalpy

d) chemical reactivity e) magnetic behaviour f) atomic size

9. What is actinoid contraction? Why is it more pronounced than lanthonoid contraction?

10. Compare the general characteristic of first row transition metals with those of second and

third series metals in the respective vertical columns with reference to

a) electronic configurationb) oxidation state c) ionization enthalpies d) atomic size.

11. Compare the stability of +2 oxidation state for the elements of the 3d series.

12. Cr2+(aq) is a better reducing agent than Fe2+ despite the half filled stability of Fe3+

Why?

13. Which transition metal exhibit only one oxidation state. Why?

14.Explain preparation of potassium dichromate. 15.

Outer electronic configuration of elements

a) X= 4f1 5d1 6s2

b) Y=4f7 5d0 6s2

Determine the

a) atomic numbers of X and Y

b) Stable oxidation states of X and Y.

c) Which is an oxidizing agent and which is a reducing agent? Why?

16. Outer electronic configuration of element X is 5f7 6d0 7s2 Determine the atomic

number of the element. What is the stable oxidation state of this element?

17. Draw the structures of a) manganate ionb) permanganate ion c) chromate ion and d)

dichromate ion.

of 22

18. What is disproportionation reaction? Give the reaction involving

disproportionation of

a) Cu+ ion b) MnO42- ion.

19. Discuss the general properties of transition metals with reference to

a) electronic configuration b) atomic radius c) ionization enthalpy

d) oxidation state e) magnetic behavior f) colored compounds

g) complex formation h) catalytic behavior i) interstitial compounds

j) alloy formation k) electrode potential (M2+ / M and M3+ / M2+k) stability of higher

oxidation state

20. What are transition metals? Which three elements are not considered as transition metals

though they are kept in d block? In which way the electronic configuration of transition

element differ from non transition elements?

21. Compare the stability of +2 oxidation state of the elements with electronic configurations 3d64s2, 3d24s5 and 3d34s2.

22. A colored compound A when fused with alkali gives a green colored compound B. B on

Electrolysis gives a purple colored compound C. Identify the compounds. Write the

reactions involved. Also write the equation of the reaction involved in the

disproportination reaction of B in acid medium.

23. Determine the number of unpaired electrons in Mn2+ ion. Calculate the magnetic

moment in Bohr maneton unit.

24. Which transition element exhibit only one oxidation state? Why?

25. An element X has atomic number 58 and another element Y has atomic number 95.

a) Give the ground state electronic configuration of X and Y.b) Give their stable oxidation

state. c) Is X an oxidizing or reducing agent? Why?d) Is Yan oxidizing or reducing agent?

Why?

26. In which way the variation in oxidation state of transition metal differ from representative

elements?

UNIT 4 CHEMICAL KINETICS 1 Following graph is between time vs concentration. What is the order of the reaction?

CONC

of 22

2 A first order reaction is 50% complete in 36 minutes at 300K. The same reaction is

50% complete in 9 min at 350K. Calculate the energy of activation of the reaction.

3.In a first order reaction a substance undergoes 75% decrease in concentration in

32 min. Calculate the half life.

Explain the following:

4 i. An increase of 10K in temperature really doubles the kinetics energy of particles

but this increase in temperature may be enough to double the vote of reaction.

ii. One gram of pulverized wood burns faster than one gram of log of wood.

5 At 3800C, the half life period for the first order decomposition of H2O2 is 360 min.

The energy of the activation of the reaction is 200KJmol-1. Calculate the time

required for 75% completion at 4500C?

6 The population of India in 1998 was 800 millions. What will be the population in

2000 if there is no change in present growth rate which is 25 per thousand per year?

It obeys first order kinetics.

Prepared by:

XI-XII Boys Section

INTERNATIONAL INDIAN SCHOOL, RIYADH WORKSHEET …4. the acid strength decreases in the order...

Documents

Transcript of INTERNATIONAL INDIAN SCHOOL, RIYADH WORKSHEET …4. the acid strength decreases in the order...