Chemistry Exam Preparation Questions and Answers

1.	An element belongs to Group 15 and third period of the periodic table. Its electonic configuration will be (A) 1s22s22p3 (B) 1s22s22p4 (C) 1s22s22p63s23p3 (D) 1s22s22p63s23p2	Answer: (C)
2.	An example for autocatalysis is (A) oxidation of NO to NO2 (B) oxidation of SO2 to SO3 (C) decomposition of KClO3 to KCl and O2 (D) oxidation of oxalic acid by acidified KMnO4	Answer: (D)
3.	Anhydrous ferric chloride is prepared by (A) Dissolving Fe(OH)3 in concentrated HCl (B) Dissolving Fe(OH)3 in dilute HCl (C) Passing dry HCl over heated iron scrap (D) Passing dry Cl2 gas over heated iron scrap	Answer: (D)
4.	At pH = 4 glycine exists as (A) H3 - CH2 - COO- (B) H3- CH2 - COO- (C) H2N - CH2 - COOH (D) H2N - CH2 - COO-	Answer: (B)
5.	By heating phenol with chloroform in alkali, it is converted into (A) salicylic acid (B) salicylaldehyde (C) anisole (D) phenyl benzoate	Answer: (B)
6.	Carbon cannot reduce Fe2O3 to Fe at a temperature below 983 K because ______. (A) CO is thermodynamically more stable then Fe2O3 (B) free energy change for the formation of CO is more negative then that of Fe2O3 (C) iron has higher affinity towards oxygen then carbon (D) carbon has higher affinity towards oxygen then iron	Answer: (C)
7.	Chemical reactions with very high Ea values are generally (A) very fast (B) very slow (C) moderately fast (D) spontaneous	Answer: (B)
8.	Consider the following gaseous equilibria with equilibrium constants K1 and K2 respectively. SO2 (g) + O2 (g) ⇌ SO3 (g) 2SO3 (g) ⇌ 2SO2 (g) + O2 (g) The equilibrium constants are related as ______. (A) (B) (C) (D)	Answer: (A)
9.	Decreasing order of reactivity of hydrogen halide acids in the conversion of ROH ® RX is (A) HCI > HBr > HI > HF (B) HI > HBr > HCI > HF (C) HF > HCI> HBr > HI (D) HF > HBr > HI > HCI	Answer: (B)
10.	During the adsorption of Krypton on activated charcoal at low temperature; ______. (A) ΔH > 0 and ΔS < 0 (B) ΔH < 0 and ΔS < 0 (C) ΔH < 0 and ΔS > 0 (D) ΔH > 0 and ΔS > 0	Answer: (B)
11.	During the fusion of an organic compound with sodium metal, nitrogen of the compound is converted into (A) NaNO2 (B) NaNH2 (C) NaCN (D) NaNC	Answer: (C)
12.	E1, E2 and E3 are the emfs of the following three galvanic cells respectively: (i) Zn (s) | Zn2+ (0.1 M) || Cu2+ (1M) | Cu (s) (ii) Zn (s) | Zn2+ (1 M) || Cu2+ (1M) | Cu (s) (iii) Zn (s) | Zn2+ (1 M) || Cu2+ (0.1M) | Cu (s) Which one of the following is true? (A) E1 > E2 > E3 (B) E2 > E1 > E3 (C) E3 > E2 > E1 (D) E3 > E1 > E2	Answer: (A)
13.	Equal weights of CH4 and H2 are mixed in a container at 25°C. Fraction of total pressure exerted by methane is (A) 1/2 (B) 1/3 (C) 1/9 (D) 8/9	Answer: (C)
14.	Ethyl benzene CANNOT be prepared by ______. (A) Wurtz-Fittig reaction (B) Wurtz reaction (C) Clemmensen reduction (D) Friedel-Crafts reaction	Answer: (B)
15.	Excess of silver nitrate solution is added to 100 ml of 0.01 M Pentaaqua chloro chromium (III) chloride solution. The mass of silver chloride obtained in grams is [Atomic mass of silver is 108] (A) 143.5 ´ 10-3 (B) 287 ´ 10-3 (C) 287 ´ 10-2 (D) 143.5 ´ 10-2	Answer: (B)