Q.26 For reaction A B, the rate constant k = A eEa1 / RT and for the reaction P Q, the rate Ea constant k2 = A2 e 2 / RT . If A = 108 A2 = 1010 and Ea1 = 600 cal/mol, Ea2 = 1200 cal/mol, then the temperature at which k1 = k2 is (R = 2 cal/K-mol) 300 4.606 (A) 600 K (B) 300 × 4.606 K (C*) 4.606 K (D) 600 K Q.27 HCl total No. of Markwonikoff 's products in above reaction is (A) 1 (B) 3 (C*) 2 (D) 4 [Sol. H2 addtion is syn addition + Total 2 stereoisomers. Ans. C] Q.28 The correct solubility order is / are (I) CaCO3 > SrCO3 > BaCO3 (II) Li2CO3 < Na2CO3 < K2CO3 (III) K2CO3 < Rb2CO3 < Cs2CO3 (IV) Na2CO3 > K2CO3 > Rb2CO3 (A) II, IV (B) I, IV (C) II, III, IV (D*) I, II, III Q.29 Calculate the maximum work done by the gas when pressure on 10 gm of H2 is reduced from 20 to 2 atm at constant temperature of 300 K. The gas behaves ideally. (A*) 28.72 kJ (B) 28.72 J (C) 2.872 kJ (D) 2.872 J Q.30 Arrange in order of decreasing reactivity in electrophilic addition (I) Ph CH = CH COOH (II) p–NO2–C6H4–CH=CH COOH (III) p–MeO C6H4CH = CH COOH (IV) p–ClC6H4CH = CHCOOH (A) II >I > IV > III (B) III > IV > I > II (C*) III > I > IV > II (D) II > IV > I > III Q.31 The structure of B3N3H6 is as follows How many derivative structures of B3N3H4X2 can be derived from the basic structure, by the replacement of two hydrogen atoms? (A) 2 (B) 3 (C*) 4 (D) 5 Q.32 The difference in H and U from combustion of solid benzoic acid(s) at 300 K is equal to (A*) –1.247 kJ (B) +1.247 kJ (C) –1.247 J (D) +1.247 J Q.33 Correct order of rate of hydrolysis for following compounds is [I] [II] [III] [IV] (A*) III > II > IV > I (B) I > II > III > IV (C) III > I > II > IV (D) III > II > I > IV [Sol. 1–bromotriptycine is 1023 times less reactive than Ph3C–Br which is 1011 times less reactive than tropylium bromide ] Q.34 Select incorrect statement regarding silver extraction process (A) When the lead-silver alloy is rich in silver, lead is removed by the cupellation process. (B) When the lead-silver alloy is rich in lead, lead is removed by parke's or pattinson's process. (C*) Zinc forms an alloy with lead, from which lead is separated by distillation (D) Zinc forms an alloy with silver, from which zinc is separated by distillation. Q.35 Equilibrium constant for the given reaction is K = 1020 at temperature 300 K A(s) + 2B (aq) l 2C (s) + D (aq) K = 1020 The equilibrium conc. of B starting with 1 mole of A and 1/3 mole/litre of B is (A*) ~ 4 ×10–11 M (B) ~ 2 ×10–10 (C) ~ 2 ×10–11 (D) ~ 10–10 Q.36 How many alkyl chlorides (without considering stereoisomers) would yield 1,3- dimethyl-cyclohexane on conversion into the grignard reagent followed by treatment with absolute ethanol. (A) 3 (B) 4 (C*) 5 (D) 6 [Sol. (1) (2) (3) (4) (5) ] Q.37 SO32– + S* boil SS*O32– SS*O32– + 2H+ H2SO3 + S* The above reaction sequence proves (A*) Two sulphur atoms of thiosulphate are not equivalent (B) Both are