Practice Questions

Q38.Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Order of acidic nature of the following compounds is A > B > C. Reason R: Fluoro is a stronger electron withdrawing group than Chloro group. In the light of the above statements, choose the correct answer from the options given below : (1) A is false but R is true (2) Both A and R are correct and R is the correct explanation of A (3) A is true but R is false (4) Both A and R are correct but R is NOT the correct explanation of A

Q38. A2 + B2 →2 AB. ΔHf = −200 kJ mol−1 AB, A2 and B2 are diatomic molecules. If the bond enthalpies of A2, B2 and AB are in the ratio 1 : 0. 5 : 1, then the bond enthalpy of A2 is _________kJ mol–1 (Nearest integer) Q39. 25. 0 mL of 0. 050 M Ba (NO3)2 is mixed with 25. 0 mL of 0. 020 M NaF. Ksp of BaF2 is 0. 5 × 10–6 at 298K. The ratio of [Ba2+][F−]2 and Ksp is ______.

Q38.Decreasing order of reactivity towards electrophilic substitution for the following compounds is: (1) d > a > e > c > b (2) e > d > a > b > c (3) a > d > e > b > c (4) c > b > a > d > e

Q38.A compound is formed by two elements X and Y . The element Y forms cubic close packed arrangement and those of element X occupy one third of the tetrahedral voids. What is the formula of the compound? (1) X2Y3 (2) X3Y2 (3) X3Y (4) XY3

Q38.The titration curve of weak acid vs. strong base with phenolphthalein as indicator is shown below. The Kphenolphthalein = 4 × 10−10 Given: log 2 = 0. 3 The number of following statement/s which is/are correct about phenolphthalein is _______ A. It can be used as an indicator for the titration of weak acid with weak base. B. It begins to change colour at pH = 8. 4 C. It is a weak organic base D. It is colourless in acidic medium Q39. 2 IO−3 + xI−+ 12H+ →6I2 + 6H2 What is the value of x ? (1) 2 (2) 12 (3) 10 (4) 6

Q38.Which one among the following metals is the weakest reducing agent? (1) K (2) Rb (3) Na (4) Li

Q38.Using column chromatography, mixture of two compounds ‘A’ and ‘B’ was separated. ‘A’ eluted first, this indicates ‘B’ has (1) low Rf, stronger adsorption (2) high Rf, weaker adsorption (3) high Rf, stronger adsorption (4) low Rf, weaker adsorption

Q38.Which hydride among the following is less stable? (1) BeH2 (2) HF (3) NH3 (4) LiH

Q38.The decreasing order of hydride affinity for following carbocations is: (a) (2) (3) (4) Choose the correct answer from the options given below: (1) C, A, D, B (2) C, A, B, D (3) A, C, D, B (4) A, C, B, D

Q38.An analyst wants to convert 1 L HCl of pH = 1 to a solution of HCl of pH = 2. The volume of water needed to do this dilution is _____ mL. (Nearest integer)

Q38.At 298 K, the solubility of silver chloride in water is 1. 434 × 10−3 g L−1 . The value of −logKsp for silver chloride is (Given mass of Ag is 107. 9 g mol−1 , and mass of Cl is 35. 5 g mol−1 )

Q38.Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Amongst He, Ne, Ar and Kr; 1 g of activated charcoal adsorbs more of Kr. Reason R: The critical volume Vc (cm3 mol – 1 ) and critical pressure Pc (atm) is highest for Krypton but the compressibility factor at critical point Zc is lowest for Krypton. In the light of the above statements, choose the correct answer from the options given below. (1) A is true but R is false (2) A is false but R is true (3) Both A and R are true but R is NOT the correct (4) Both A and R are true and R is the correct explanation of A explanation A

Q38.In the depression of freezing point experiment A. Vapour pressure of the solution is less than that of pure solvent B. Vapour pressure of the solution is more than that of pure solvent C. Only solute molecules solidify at the freezing point D. Only solvent molecules solidify at the freezing point (1) A and D only (2) B and C only (3) A and C only (4) A only

Q38.In sulphur estimation. 0. 471 g of an organic compound gave 1. 4439 g of barium sulphate. The percentage of sulphur in the compound is _______(Nearest Integer) (Given: Atomic mass Ba: 137u : S : 32u, O : 16u )

Q38.In which of the following reactions the hydrogen peroxide acts as a reducing agent? (1) PbS + 4H2O2 →PbSO4 + 4H2O (2) 2 Fe2+ + H2O2 →2 Fe3+ + 2 OH− (3) HOCl + H2O2 →H3O+ + Cl−1 + O2 (4) Mn2+ + H2O2 →Mn4+ + 2 OH−

Q38.On heating, LiNO3 gives how many compounds among the following? Li2 O, N2, O2, LiNO2, NO2

Q38.Which of the following reaction is correct? (1) Δ (2) Δ 2 LiNO3 →2 LiNO2 + O2 4 LiNO3 →2 Li2 O + 2N2O4 + O2 (3) Δ (4) Δ 4 LiNO3 →2 Li2 O + 4 NO2 + O2 2 LiNO3 →2Li + 2 NO2 + O2

Q38.Given below are two statements: Statement-I : Methyl orange is a weak acid. Statement-II : The benzenoid form of methyl orange is more intense/deeply coloured than the quinonoid form. In the light of the above statement, choose the most appropriate answer from the options given below: (1) Both Statement-I and Statement-II are incorrect(2) Statement-I is incorrect but Statement-II is correct (3) Both Statement-I and Statement-II are correct (4) Statement-I is correct but Statement-II is incorrect

Q39.The magnetic behaviour of Li2 O, Na2 O2 and KO2 , respectively, are (1) diamagnetic, paramagnetic and diamagnetic (2) paramagnetic, paramagnetic and diamagnetic (3) paramagnetic, diamagnetic and paramagnetic (4) diamagnetic, diamagnetic and paramagnetic

Q39.Arrange the following compounds in increasing order of rate of aromatic electrophilic substitution reaction. (1) d, b, c, a (2) d, b, a, c (3) b, c, a, d (4) c, a, b, d

Q39.Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Gypsum is used for making fireproof wall boards. Reason (R): Gypsum is unstable at high temperatures. In the light of the above statements, choose the correct answer from the options given below: (1) Both (A) and (R) are correct but (R) is not the (2) (A) is correct but (R) is not correct. correct explanation of (A). (3) (A) is not correct but (R) is correct. (4) Both (A) and (R) are correct and (R) is the correct explanation of (A).

Q39.The volume of 0. 02 M aqueous HBr required to neutralize 10. 0 mL of 0. 01 M aqueous Ba(OH)2 is (Assume complete neutralization) (1) 2. 5 mL (2) 5. 0 mL (3) 10. 0 mL (4) 7. 5 mL

Q39.The solubility product of BaSO4 is 1 × 10−10 at 298 K. The solubility of BaSO4 in 0. 1M K2 SO4(aq) solution is ------ ×10−9 g L−1 (nearest integer). Given: Molar mass of BaSO4 is 233 g mol−1

Q39.Identify the correct statements about alkali metals. A. The order of standard reduction potential (M+ | M) for alkali metal ions is Na > Rb > Li. B. CsI is highly soluble in water. C. Lithium carbonate is highly stable to heat. D. Potassium dissolved in concentrated liquid ammonia is blue and paramagnetic. E. All alkali metal hydrides are ionic solids. Choose the correct answer from the options given below (1) A, B, D only (2) C and E only (3) A and E only (4) A, B and E only

Q39.Which of the following represents the correct order of metallic character of the given elements? (1) Si < Be < Mg < K (2) Be < Si < Mg < K (3) K < Mg < Be < Si (4) Be < Si < K < Mg