Gujarat Board Class 12 Chemistry Previous Year Question Papers 2007

Instructions :
1. This question paper has total
60 questions and all are compulsory.
2. Write your answer to the point and as instructed in the question.
3. Begin new section from new page and maintain the order of questions.
4. Use log-table or simple calculator for calculations.
5. Draw a neat and clean diagram with necessary labellings, wherever
required.
Atomic weights :
H = 1, 0 = 16, K = 39, Mn = 55 gms/mole

SECTION - A

Question Nos. from 1 to 16 are multiple choice type. 16
Each carries ONE mark. Select the correct option from the following.

1. For which of the following sets of 4 quantum numbers an electron
will have the highest energy?
          n        1     m       s
(A)     3    2       1       1/2
(B)       4   2      -1     1/2
(C)       4   1        0    -1/2
(D)      5      0     0    -1/2
2. The number of Na+ ions filling all octahedral voids in NaCl structure
are :
(A) 6 (B) 12 (C) 13 (D) 14
3. What is the normality of 1 M KMnO4 solution?
(A) 0.1N (B) 2N (C) 0.5N (D) 5N
4. Zn gives H2 gas with H2SO4 and HCl, but not with HNO3 because
(A) NO3- is reduced before reduction of hydronium ion.
(B) HNO3 is weaker acid than H2SO4 and HCI.
( C) In electrochemical series Zn is above hydrogen.
( D) Zn acts as an oxidizing agent when reacts with HNO3.
5. The second order rate constant is usually expressed as
(A) mole liter sec-1 (B) mole-1 liter -1 sec-1
(C) mole liter-1 sec-1 (D) mole-1 liter sec-1
6. ZSM-5 converts
(A) Benzene to Toluene (B) Alcohol to Petrol.
(C) Toluene to Benzene (D) Heptane to Toluene
7. An element (X) forms compounds of the formula XC13, X205 and
Ca3X2, but does not form XC15. Which of the following is the element  X?
(A) B (B) Al
(C) N (D) P
8. What is responsible for the stability of +3 oxidation state in inner
transition elements?
(A) Ionization energy.
(B) Hydration energy.
(C) Ionization energy and Hydration energy.
(D) Electronic configuration.

11. Which of the following alcohol will not be easily oxidized by K2Cr2O7
in dil. H2SO4?
(A)CH3OH (B) CH3.CH2.OH (C)(CH3)3.C.OH (D) CH3CH.OH.CH3
12. Identify the wrong statement from the following.
(A)    Salicylic acid is monobasic acid.  
(B)    Methyl salicylate is an ester.
(C)      Salicylic acid gives violet colour with neutral FeC13 as well as brisk effervescence with NaHCO3
(D)       Methyl salicylate does not occur in natural oils.

13. Dimethylterephthalate and ethylene glycol react to form ......
(A) Nylon 6 (B) Nylon 66
(C) Decron (D) Neoprene
14. Two vitamins absorbed from the intestine along with fats are
(A) A, D (B) A, B
(C) A, C (D) D, B
15. The compound is used as....
(A) antiseptic (B) antibiotic
(C) analgesic (D) pesticide
16. A 16 year old boy came to the doctor with main complaints of
frequent sneezing, watering from nose and eyes, intense itching in
eyes, and cold. He has past history of allergy to dust. The doctor
prescribes most probably which of the following drugs.
(A) Norethindrone (B) Lansoprazole
(C) Reserpine (D) Chlorpheniramine
SECTION - B

Question Nos. from 17 to 32 are very short answer type questions.

Each question carries ONE mark.
17. State the relationship of cartesian co-ordinates x, y and z to spherical
polar co - ordinates r, 0 and 4.
18. Give examples, one of each, of ferromagnetic and anti-ferromagnetic
substances.
19. How many atoms are needed for the formation of one unit cell of bcc
configuration? Why?
20. For which reaction, the Enthalpy will be zero?
21. In the flue cell, the electroenergy produced during the formation of
1 mol H2O (1) is equal to 50 K.cal. and standard free energy of water
is 68.32 K. cal./mol. Find out the efficiency of the Flue cell.
22. Give the structural formula of 0-hydroxy amino ethyl benzoate.
23. What is Tyndall effect?
24. Give the equation of obtaining Sodium salt of triphosphoric acid.
25. Write the theoretical and practical electron configuration of Cerium
(Z = 58).
26. Give the formula and IUPAC name of Sodium Nitroprusside.
27. Sodium's stable isotope is 11Na23.If we take 11Na24, it shows whichtype of radioactivity? Show it by equation.
28. What is causing fermentation of D-glucose? And which glucose is notfermented by the same.
29. Show the possible isomers of C6H602 with their common names. (any two).
30. Complete the equation. Conc. H2SO4 CH3.CN + CH3.CH2.OH + H2O 0 Acetonitrile Ethenol
31. Give the basic difference between glycylalanine and alanyl glycine.
32. What is Leuco salt?SECTION - C
Question Nos. from 33 to 48 are short answer type Questions.
32
Each question carries TWO marks.
33. Give molecular electron configuration of 02 molecule and explain its
magnetic properties.
OR
What is Van der Waals' attraction? On which factors do it depend?
34. What is Hybridization? Give hybridization, geometrical shape and
bond angle of Fe(CO)5.
35. Write a short note on : Frenkel Defects.
36. Find out mole fractions of solute and solvent of 1 molal aqueous
solution.
OR
How many millimoles of CO2 will dissolve in 900 ml water, when
CO2 gas is passed from water at 25°C.
37. Explain the expansion of ideal gas in vacuum and change in Entropy.
38. Write Second Law of Thermo-dynamics and its limitations.
39. Give the structural formulas of Phosphonic acid and Pyrophosphoric
acid.
OR
Give the equation of Aluminium with dil. HC1 and cone. alkali.
40. "Although first ionization energy is less than second ionization
energy, M1+ compounds of transition elements can not be made
easily in comparison to M2+ compounds." Explain.
OR
Mention the uses of Lanthanides. (any four)
41. [Ni F4]2- is diamagnetic, whereas [Ni (CN)4]2- is paramagnetic.
Explain.
42. Write a note on Breeder Reactor.
43. Calculate the energy released in the following fusion reaction.
2H+ 3H->'He+ on
(Mass : 1H = 2.014; 1H = 3.016 ; He = 4.003,
n =1. 009 amu)
44. Give the organic conversion of the following.
Isopropyl Alcohol from acetaldehyde.
OR
Acetoxime from Isopropyl Alcohol.
45. Write conversion of
P-hydroxy azobenzene from Aniline.
46. Explain Carbyl test with equation (any one).
47. Mention full names, polymer structure and uses of PTFE and PAN.
48. Write a note on Pheromones.SECTION - D
Question Nos. 49 to 60 are long answer type questions.
Each question carries THREE marks. Answer the following to the point.
49. What is meant by Molal Elevation constant? Derive formula for
Molal Elevation constant.
OR
What is meant by Molal Depression constant?
Derive formula for Molal Depression constant.
50. The potential of the following given cell is 0.59 volt. Calculate the
ionic product of Water (Kw).
Pt / H2(1 atm) / KOH(o.01M) // HCl(o.o1M) / H2 (1 atm) / Pt
OR
Calculate cell voltage of the following electrochemical cell at 25°C
and write cell reaction.
Al / Al2(SO4)3 (aq) // CuSO4 (aq) / Cu (1 M) (0.02 M) (E°A13+/Al = -1.66 V ; E°Cu/Cu2+ =-0.34V)
51. The decomposition of N205 dissolved in Carbon tetrachloride
decomposes at definite temperature as follows.
N₂0₅ (solution) = 2 NO2 (solution) +1/2 02(g)
This reaction is of 1st order and its rate constant is 5.0 x10-4 sec-1.
For this reaction initial conc. of N₂0₅ is 0.25 mole / litre.
(i) What time will be required for completion of 75% of reaction?
(ii) What will be the concentrations of N₂0₅ and NO₂ after
30 minutes from the start of the reaction
52. Derive formula of Langmuir Absorption Isotherm and express the
equation at low and high pressure situations.
53. Give only equations of production of Chlorine and Iodine.
OR
Mention equations of the formation of XeF2, XeF4 and XeF6 with
their structures.
54. Write points of tendency of transition metal ions to form complex
compounds.
55. Explain hybridization, geometrical shape and magnetic properties of
complex compound K4[Fe(CN)6].
OR
Show geometrical isomers in cis-trans and facial meridonial results
of metal ion Fe and Co bearing 6 co-ordination number.
56. Explain steps of R & S nomenclature.
57. Explain and give equations of industrial manufacturing of Salicylic
acid by Kolbe-Schmitt reaction.
58. Explain Wolff-Kishner and Clemmenson reduction reactions.
OR
Give only equations of dehydration reactions of amides and its
Hoffman reaction.
59. Explain Filler, Plasticizer and Anti-oxidants.
60. Explain classification of Lipids.