Chemistry important model question paper
Class 12th is most important period of career and chemistry is considered as one of toughest subject of class 12th especially for students who are good in physics. Here we have tried to get you more practiced for class 12th chemistry and so we have brought before you 12th chemistry important model question paper
12th chemistry important model question paper
PART – I
Choose and write the correct answer:
1. Which of the following particles having same kinetic energy would have the maximum debroglie wavelength?
a) Proton b) neutron c) α – particle d) β – particle
2. Intra – molecular hydrogen bonding is present in
a) HF b) O – Nitro phenol c) ethanol d) tri bromo phenol
3. If XA – XB = 0 the bond is
a) Non polar covalent b) polar covalent c) ionic bond d) co – ordinate covalent
4. The compound with garlic odour is
a) P4O6 b) P2O5 c) H3PO3 d) PH3
5. The ion with maximum number of unpaired electrons is
a) Mg2+ b) Ti3+ c) V3+ d) Fe2+
6. The correct electronic configuration of copper atom is
a) 3d104sf b) 3d104s2 c) 3d94s2 d) 3d54s24p4
7. Maximum oxidation state exhibited by lanthanide is
a) +1 b) +2 c) +3 d) +4
8. The isotope used as a power source in long mission space probes is
a) U235 b) Pu235 c) Pu238 d) U238
9. An example of chelating ligand is
a) Chloro b) bromo c) en d) NO2–
10. Which of the following is used as neutron absorber in the nuclear reactor?
a) Water b) deuterium c) uranium d) cadmium
11. An ion leaves its regular site and occupies a position in the space between the lattice sites.
a) Schottky defect b) Frenkel defect c) Vacancy defect d) Impurity defect
12. Change in Gibbs free energy is given by
a) ΔG=ΔH+TΔS b) ΔG=ΔH-TΔS c) ΔG=ΔH×TΔS d) ΔG=ΔE+PΔV
13. If ΔS for a reaction is negative, the change is
a) spontaneous b) reversible c) non spontaneous d) equilibrium
14. In the reversible reaction 2H2O(g)+2Cl2(g) → 4HCl(g)+O2(g),Kp is
a) greater than Kc b) less than Kc c) equal to Kc d) zero
15. In the equilibrium N2(g)+3H2(g) → 2NH3(g) the maximum yield of ammonia will obtained with the process having
a) low p high T b) high p low T c) high T high P d) low T low P
16. Arrhenius equation is
a) K=Aae-1/RT b) K=AeRT/Ea c) K=Ae-Ea/RT d) K=AeEa/RT
17. Smoke is a colloidal solution of
a) gas in liquid b) liquid in gas c) gas in solid d) solid in gas
18. An emulsion is a colloidal solution of
a) two solids b) two liquids c) two gases d) one solid one gas
19. Bergius process for the synthesis of petrol from coal the catalyst used is
a) Fe2O3 b) CuCl2 c) V2O5 d) NO
20. Oswalds dilution law is applicable in the case of the solution of
a) CH3COOH b) NaCl c) NaOH d) H2SO4
21. oxidation of glycerol with bismuth nitrate gives
a) meso oxalic b) glyceric c) tartronic acid d) both b and c
22. Oxygen atom of ether is
a) very active b) inert c) oxidizing d) replaceable
23. Anisole is used in
a) perfumes b) ananesthetic c) antiseptic d) solvent
24. Hydrogeneration of benzoyl chloride in the presence of Pd and BaSO4 gives
a) phenol b) benzoic acid c) benzyl alcohol d) benzaldehyde
25. Weakest acid among the following compounds
a) CH3COCH b) C6H5OH c) H2O d) C2H2
26. Bromo ethane reacts with silver nitrite to give
a) C6H5NO2 b) C2H5-O-NO c) C2H5Br d) C2H5NC
27. Which one is known as oil of mirbane?
a) nitro methane b) nitro ethane c) nitro benzene d) methyl amine
28. The order of boiling point in amines depending upon strength of hydrogen bond is
a) 1°>2°>3° b) 3°>2°>1° c) 2°>°1>3° d) 2°>3°>1°
29. The building block of proteins are
a) α – hydroxyl acids b) α – amino acids c) β – hydroxyl acids d) β – amino acids
30. The reducing sugar is
a) sucrose b) cellulose c) starch d) glucosePART – II Answer any 15 Question
31. Distinguish between particle and wave.
32. If C-Cl bond distance is 1.76 A° and atomic radius of chlorine is 0.99 A°, calculate the atomic radius of Carbon.
33. Write a note on plumbo solvency?
34. Why transition elements from complexes?
36. A substance is found to have a magnetic moment of 3.9 BM. How many unpaired electrons does it Contain?
37. What are four decay series?
38. Calculate the number CsCl units per unit cell?
39. What is entropy? What are the units of entropy?
40. Define – Reaction quotient ‘Q’.
41. What is activation energy?
42. What are simple and complex reactions?
43. What is heterogeneous catalyst? Give example?
44. The mass of the substance deposited by the passage of 10 ampere of current for 2 hrs 40 mins and 50 seconds is 9.65g. Calculate the electrochemical equivalent.
45. What are the conditions for a compound to be optically active?
46. How is allyl alcohol obtained from glycerol?
47. Phenol is insoluble in NaHCO3 solution but CHCOOH is soluble. Give reason.
48. Write a note on Rosenmund Reduction?
50. Write carbylamines reaction.
51. What are anesthetics? Give example.
PART – IIIAnswer any seven questions choosing at least two question from each section 7×5 = 35 Section – A
52. Derive de-Broglie’s equation. What is its significance?
53. Explain how potassium dichromate is extracted from chromite ore.
54. Bring out the consequences of lanthanide contraction.
55. Write the postulates of werner’s theory.Section – B
56. State various statements of second law of thermodynamics.
57. State Le chartlier’s principle. How this principle used for the formation of NH3
58. Write notes on
(i) consecutive reaction (ii) parallel reaction (iii) opposing reaction
59. The emf of the half cell Cu2+(aq)/Cu(s) containing 0.01 M Cu2+ solution is +0.301 V Calculate the standard emf of the half cell.Section – C
60. Distinguish between aromatic and aliphatic ethers.
61. Discuss the mechanism of aldol condensation.
62. How are the following conversation carried out?
(i) Salicylic Aspirin
(ii) Lactic acid Lactide
63. Explain briefly characteristics of rocket propellants?
Question No. 70 compulsory and answer any three from the remaining questions. 4×10=40
64. a) Explain the various factors that affect ionisation energy.
(b) Mention the uses of silicones.
65. (a) In what way [FeF6]4-
(b) Explain radio carbon dating
66. (a) Explain the nature of glass.
(b) Write briefly about the preparation of colloids by chemical methods.
67. (a) Derive Henderson equation
(b) How emf of a cell is determined?
68. (a) Describe the conformation of cyclo hexanol comment on their stability.
(b) Give the mechanism involved in the satisfaction of a carboxylic acid with alcohol.
69. (a) Write note on i) Mustard oil reaction (ii) coupling reaction (iii) schiff’s base formation
(b) How is the structure determined?
a) An organic compound ‘A’ (C2H6O) reacts with metallic sodium liberates hydrogen gas and also gives red color in victor Mayer test. On oxidation with K2Cr2O7 ‘A’ gives the compound ‘B’. ‘B’ also undergoes aldol condensation . Further oxidation of ‘B’ gives compound ‘C’ compound ‘A’&’C’ reacts in the presence of H2SO4 it gives compound ‘D’ compound ‘D’ is fruity odour in nature. Identify compound A,B,C, and D. Explain the reactions.
b) ‘A’ sulphate compound of group 11. This compound is also called as Blue vitriol. The compound undergoes decomposition at various temperature
A → B → C → D
Identify the compounds A,B,C and D.
c) An organic compound ‘A’ (C6H6O) gives maximum of two isomers B & C. When alkaline solution of A is refluxed with chloroform at 333K. B on oxidation gives an acid ‘D’. The acid D is also obtained by treating sodium salt of ‘A’ with CO2 under pressure. Identify A, B, C & D and explains the reactions.
d) The equivalent conductance at infinite dilution of HCl, CH3COONa, and NaCl are 426.16, 91.0 and 126.45 ohm-1 cm2 (gm.Equivalent)-1 respectively. Calculate the λa of acetic acid.
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Chemistry important model question paper_2013_09_11_13_24_01_080
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