KV.3, AFS, BHISIANA

CHEMISTRY -X11

Time allowed 3 hours Max. marks 70

General Instructions:

(i) All questions are compulsory.

(ii) Q.no. 1-8 are very short answer question & carry 1 mark each

(iii) Q.no. 9-18 are short answer question & carry 2 marks each

(iv) Q.no. 19-27 are short answer question & carry 3 marks each

(v) Q.no. 28-30 are long answer question & carry 5 marks each

(vi) Use log tables if necessary, use of calculators is not allowed.

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1. Give the IUPAC name of the compound:

( CH3)2C=CH-COOH

2. Name one preservative used in cold drinks.

3. What happens when iodine is added to sodium chlorate? Write balanced chemical equation.

4. Write the structure of 2-ethoxy-4-methyl- pentan-3-one.

5 A compound contains “X” atoms at the corners & atoms “Y” occupy all the octahedral voids.

Write the simplest formula of the compound.

6.What is Vant hoff factor (i) if K4[Fe(CN)6] is 50%ionised?

7. What is the role of depressant in Froth Floatation process?

8. Predict the shape of ICl3 on the basis of VSEPR theory.

9. An element crystallises in cubic structure. If the density of the solid is 9.00g/cm 3 & edge of

unit cell is 3.85x10-8 cm,What is the unit cell geometry?Atomic mass of the element is 240gmol-1

10. Molar conductivity at infinite dilution for NH4Cl, NaOH &NaCl solutions at 298K are

respectively 129.8,217.4& 108.9Scm2mol-1 &Λm of 10-2 solution of NH4OH is 9.33 Scm2mol-1.

Calculate the degree of dissociation of NH4OH

11. The value of ΔG0 for the formation of Cr2O3 is -540Kj mol-1 & that of Al203 is -827Kj mol-1.

Is the reduction of Cr2O3 possible with Al?

12. What are essential & non essential amino acids? Give one example of each.

13. (a) What is meant by denaturation of proteins?

(b) Give one example each of globular & fibrous proteins.

14. Write the mechanism of dehydration of ethyl alcohol with the help of conc. H 2SO4 to give

alkene.

15. Complete the following reactions:

Cl Conc. H2SO4 (i) + HNO3( conc.)

(ii) C2H5Cl + AgCN

16. Give the chemical test to distinguish between

(i) Ethyl amine & di ethyl amine

ll) Butane-1-ol & 2-methyl-2-propanol

17. Write short note on

(i) Hoffmann Bromamide reaction

(ii) HVZ reaction

OR

17. Give reasons:

(i) Aldehydes are more reactive than ketones in nucleophilic addition reactions.

(ii) During preparation of ammonia derivative of aldehydes & ketones pH of a medium is

controlled.

18.(a)What are ideal solution ? Give one example

(b) What happens to temperature when n-Hexane is mixed with n-Haptane & why

19. Lithium metal in bcc structure has density 0.53 gcm-3. Calculate the volume of a unit cell

of Li metal (molar mass=6.94gmol-1)?

20.Write names of monomers and classify them as addition or condensation polymers

(a)buna-N (b)bakelite

(b)Give IUPAC name of K3[Fe(CN)6].

22.Explain the following observations:-

(i)Why are powdered substance more effective adsorbents than crystalline forms?

(ii) Why chemical adsorbtion occurs at higher temperature?

(iii)What happens when ferric hydroxide sol is mixed with As2S3 sol?

23.(a)Why do halogens have maximum electron gain enthalpy ?

(b)Why is bond energy of fluorine is less than chlorine?

(c) What happens when SO2 is passed through an aqueous solution of Fe3+ ions?Write

chemical equation for the reaction?

24.(a)A first order reaction takes 69.3 minutes for 50% completion.How much time will it

take for 90% completion of the reaction?

(b)What is the effect of catalyst on the free energy change of reaction?

OR

The decomposition of Cl2O7 at 400 K in a gas phase to Cl2 and O2 is the first order reaction.

(i)After 50 seconds the pressure of Cl2O7 falls from 0.062 to 0.044 mm.Calculate the rate

constant.

(ii)Calculate the pressure of Cl2O7 after 100 seconds of decomposition at this temperature.

25.(a)Why alkyl halides have high boiling points than corresponding alkanes?

(b)Which has higher boiling point and why ?(i)n-butyl chloride (ii) secondary butyl chloride

(c) Why are aryl halides less reactive than alkyl halide towards nucleophilic substitution

reaction .

26.(a)Arrange the following in increasing order of bond angle.

(i)NH3 ,PH3,AsH3 ,SbH3,BiH3

(b) Arrange the following in increasing order of boiling point

HCl,HBr,HI,HF

(c ) Why does OF6 not exist?

OR

A compound (X) on heating with I2 gives a compound (Y) and a gas which is greenish

yellow in colour .compound (X) on heating with phosphorous pentaoxide gave a compound

(P) and HPO3. compound (X) is obtained from HClO3 along with compound (Q) which

onheating decomposes to give elements (Z) and ( R).(Z) displaces iodine from aqueous

solution of KI .identify (X),(Y),(Z),(P),(Q),(R).

27.Account for the following :

(a)Asprin should not be taken empty stomach.

(b)Antihistamines drugs are given in case of allergy.

( c) Iproniazide is used as tranquilizer.

28. (a) An unknown aldehyde ‘A’ C7H6O on reacting with KOH are gives ‘B’ and ‘C’ . ‘C’ is an

aryl alcohol.’A’ reacts with Zn(Hg) and conc. HCl to give ‘D’ which changes to ‘A’ by CrO2Cl2.

‘B’ on heating with soda lime gives ‘E’. Identify A to E and write all the reaction involved?

(b) How will you carry out following conversions (not more than 2 steps )(1) Benzaldehyde to benzophenone(2) Benzoic acid to m-nitrobenzyl alcohol(3) Ethane nitrile to Ethyl alcohol

OR

(a) An organic compound with molecular formulae C9H10O froms 2,4 -DNP derivative reduces

Tollen’s reagent and undergoes Cannizaro’s reaction .On vigourus oxidation ,it gives 1, 2-

benzene dicarboxylic acid. Identify the compound.

(b) How will you carry out the following reactions.

(1)Ethyl alcohol to acetone

(2) Ethylene to acetic acid

(C) Aniline to benzylamine

29. (a) Write e.m.f of the following Given E0Br2/2Br-=1.08 V.

Pt, Br2(l) / Br- (0.01M) || H+ (0.03M) / H2(l atm), Pt

(B)calculate the number of coulombs required to deposit 12.7 g of copper when blue vitriol is

electrolysed. (Atomic mass of Cu = 63.5g)

OR

(a) Given E0k+/k = -2.93 V, E0Ag+/Ag = +0.80V , E0Mg2+/Mg = -2.73 V, E0 Cr2+/Cr = -.74V

arrange these metals in increasing order of reducing power

(b)The conductivity of 0.20 M solution of KCl at the 298 K is .0248 S cm-1 calculate ita

molar conductivity

(c ) What happens when aq solution of CuCl2 is electrolysed using Pt electrodes.

30 .(a) What happens when pH of solution of dichromate is raised?

(b) Draw the structure of dichromate ion?

(c) Give reason

(1) Ni (11) compounds are thermodynamically more stable than Pt(11) compounds

(2) The second and third member in a group of transition elements have similar

atomic radii.

OR

(a) Why is V2O3 strongly reducing agent ?

(b) What is the value of spin only magnetic moment for d4 in strong field?

(c) What happens when alkaline KMnO4 reacts with iodide ions in reaction?

(d) What is the general electronic configuration of lanthanoides?