VIKAS PRE UNIVERSITY COLLEGE, MANGALURU ANNUAL EXAMINATION - ANSWER KEY II PUC - CHEMISTRY PART A

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1 1. Decreases 2. Negative Deviatin λ = λ + λ. ( NaCl ) + Na Cl VIKAS PRE UNIVERSITY CLLEGE, MANGALURU ANNUAL EXAMINATIN - ANSWER KEY II PUC - CEMISTRY PART A 4. Number f cllisins taking place per secnd per unit vlume f the reactin mixture. 5. Activated charcal 6. Nickel 7. Argn 8. Fittig Reactin 9. N α - hydrgen present in frmaldehyde 10. Vitamin C PART B 11. Crystalline slids * They have definite gemetrical shape Amrphus slids * They d nt have definite gemetrical shape * They have sharp melting * They d nt have sharp pint melting pint. 12. Cathde: e 4 2( g ) 2 ( l) ( aq) Ande: e 2( g ) ( aq) 2 ( l) 1. First rder reactin Unit = s The gradual decrease in the atmic and inic radii f lanthanide elements due t pr shielding f 4f electrns. 15. Anisle reacts with acetyl chlride in the presence f anhydrus aluminium chlride as catalyst t frm 2 methxy acetphenne and 4 methxy acetphenne. C 2 C CCl C CC C anly. AlCl Cl (Anisle) 2 - methxy acetphenne CC 4 - methxy acetphenne 1

2 16. Benzic acid reacts with ammnia t give ammnium benzate. n further heating gives Benzamide. C CN 4 CN 2 N - 2 (Benzamide) 17. i) Aspirin ii) Furacine 18. Aninic Detergents are sdium salts f sulphnated lng chain alchls r hydrcarbns. Eg: Sdium Laurylsulphate. PART C 19. i) 20. ii) 2 Al 2 + C 4Al + C 2 iii) Ande N N Temperature = 700K and Pressure = 200 atm.

3 21. i) xygen shws a cvalency f 2 in general and rarely 4. xygen is a gas while ther elements are slids at rm temperature. ii) Cu S 4 CuS 4 + S i) a) 2Na + Cl2 NaCl + NaCl + 2 ( cld and dil) b) Cl + F 2ClF ( excess) ii) Chlrus acid Cl 2. i) µ = n( n + 2) = 4(4+ 2) = 4.89 BM ii) Magnaneese 24. KMn 4 is prepared by fusin f Mn 2 with alkali metal hydrxide and an xidizing agent Like KN. This prduces the dark green K 2 Mn 4 which n acidificatin gives permanganate. 2Mn + 4K + 2K Mn Mn + 4 2Mn + Mn ybridisatin dsp i). Gemetrical shape Square planar Magnetic prperly Diamagnetic ii) Six N Fe (cis) N N Fe N (trans) 27. a) PART D

4 In fig., the edge length r side f the cube be a, and the radius f each particle be r. a = 2r Vlume f cube = a ( 2r) = 8r In simple cube, each unit cell has nly ne sphere, Vlume f sphere = 4 π r Vlume f a sphere Packing efficiency = 100% Vlume f the cube 4 π r = 100 = 52.4% 8r b) 28. a) 29. a) Z M Density = a N = ( ) = g/cm. a W2 K f M 2 = = = 256 g / ml T W f 1 b) Decreases with respect t increase in temperature. n increasing pressure, slubility f gas increases. G Zn + Cu Zn + Cu = n F E Cell = = Jules. b) i) Nature f the electrlyte ii) Temperature f the slutin. 0. a) Cnsider a zer rder reactin R P d [ R] Rate = = k[ R] dt 4

5 d [ R] = k [ R ] dt d [ R] dt = k d[r] = -k. dt Integrating n bth sides [R] = - kt + I..(1) When t = 0, [R] = [R] 0 By substituting [R] 0 = I in equatin (1), we get, 1. a) [R] = - kt + [R] 0 [ R] 0 [ R] k = t b) i) k = Ae -Ea/Rt ii) t 1 2 [ R] = 2k 0 Lyphilic Sl Lyphbic Sl Reversible Irreversible Stable Unstable b) Step 1: Binding f enzyme t substrate t frm an activated cmplex E + S ES * Step 2: Decmpsitin f the activated cmplex t frm prduct ES * E + P c) S < V. 2. a) Cl Cl -Cl b) i) Due t resnance effect ii) sp 2 hybridised carbn c) The carbn atm which is bnded t fur different atms/grups. 5

6 . a) Sdium phenxide generated by treating phenl with sdium hydrxide. It is treated with carbn dixide t frm rth hydrxybenzic acid ( salicylic acid) Na Na i) C 2 C ii) + b) Step 1: Prtnatin f Alchl C C C C Step 2: Frmatin f Carbcatin C C C C - 2 Step : Eliminatin f prtn t frm Ethene C C - C Zn - g Cl C 2 C C 4. a) When vapurs f C and Cl are passed int benzene in the presence f anhydrus AlCl /CuCl, Benzaldehyde is btained. b) c) Increases C + Cl Anley AlCl / CuCl C 5. a) Amides n treatment with brmine in an aqueus slutin f sdium hydrxide frms primary amine. R C N 2 Br 2 4 Na R - N 2 Na 2 C 2NaBr 2 2 b) i) Ethamine ii) (C ) N < C N 2 < (C ) 2 N c) C 2 5 N 2 Cl - NaCl 2 6

7 6. a) b) i) Albumin ii) Glycine c) DNA 7. a) Buna N is btained by c plymerizatin f 1, butadiene and acrylnitrile in the presence f a perxide catalyst. n C 2 C C C 2 n C 2 C b) i) Vinyl chlride ii) Isprene C 2 C C C 2 C 2 C Buna - N c) Ply β - hydrxyl butyrate c - β - hydrxylvalerate (PBV) ************ n 7