Practice Questions

Q36.A process will be spontaneous at all temperatures if: (1) ΔH < 0 and ΔS < 0 (2) ΔH < 0 and ΔS > 0 (3) ΔH > 0 and ΔS > 0 (4) ΔH > 0 and ΔS < 0

Q36.The molar solubility of Cd(OH)2 is 1.84 × 10−5M in water. The expectes solunility of Cd(OH)2 in a buffer solution of pH = 12 is: (1) 2.49 × 10−10M (2) 2.491.84 × 10−9M (3) 1.84 × 10−9M (4) 6.23 × 10−11M

Q36.In an acid-base titration, 0.1 M HCl solution was added to the NaOH solution of unknown strength. Which of the following correctly shown the change of pH of the titration mixture in this experiment? JEE Main 2019 (09 Apr Shift 2) JEE Main Previous Year Paper (1) A (2) B (3) D (4) C

Q36.For the reaction, 2SO2g + O2g ⇌2SO3g, ∆H = - 57.2 kJ mol-1 and Kc = 1.7 × 1016 . Which of the following statements is incorrect? (1) The equilibrium constant is large suggestive of (2) The equilibrium will shift in forward direction as reaction going to completion and so, no catalyst the pressure increases. is required. (3) The equilibrium constant decreases as the (4) The addition of inert gas at constant volume will temperature increases. not affect the equilibrium constant.

Q36.Consider the reversible isothermal expansion of an ideal gas in a closed system at two different temperatures T1 and T2T1 < T2 . The correct graphical depiction of the dependence of work done w vs the final volume V is: (1) (2) (3) (4) Q37.20 ml of 0.1 M H2SO4 solution is added to 30 mL of 0 .2 M NH4OH solution. The pH of the resultant mixture is: pkb of NH4OH = 4 .7 (1) 5.0 (2) 5.2 (3) 9.4 (4) 9.0 JEE Main 2019 (09 Jan Shift 1) JEE Main Previous Year Paper

Q36.Consider the reaction N2( g) + 3H2( g) ⇌2NH3( g) The equilibrium constant of the above reaction is KP . If pure ammonia is left to dissociate, the partial pressure of ammonia at equilibrium is given by (Assume that PNH3 << Ptotal at equilibrium) (1) 33/2 K1/2P P2 (2) K1/2P2P 16 16 (3) K1/2P2P (4) 33/2 K1/2P P2 4 4

Q36.An open vessel at 27oC is heated until two fifth of the air (assumed as an ideal gas) in it has escaped from the vessel. Assuming that the volume of the vessel remains constant, the temperature to which the vessel has heated is: (1) 750oC (2) 500oC (3) 750K (4) 500K

Q36.In a chemical reaction, A + 2B ⇌2CK + D , the initial concentration of B was 1.5 times of the concentration of A , but the equilibrium concentrations of A and B were found to be equal. The equilibrium constant (K) for the chemical reaction is: (1) 1 (2) 4 (3) 1 (4) 16 4

Q36.A mixture of 100 m mol of Ca (OH)2 and 2 g of sodium sulphate was dissolved in water and the volume was made up to 100 mL. What is the mass of calcium sulphate formed and the concentration of OH− in resulting solution, respectively? (Molar mass of Ca (OH)2, Na2 SO4 and CaSO4 are 74, 143 and 136 g mol−1, respectively; Ksp of Ca (OH)2 is 5 .5 ×10−6 ) (1) 1 .9 g, 0 .14 mol L−1 (2) 13 .6 g, 0 .28 mol L−1 (3) 1 .9 g, 0 .28 mol L−1 (4) 13 .6 g, 0 .14 mol L−1

Q36.In order to oxidize a mixture of one mole of each of FeC2O4, Fe2 ( C2O4 ) 3, FeSO4 and Fe2 ( SO4 ) 3 in acidic medium, the number of moles of KMnO4 is: (1) 1 (2) 2 (3) 3 (4) 1.5

Q36.Among the following, the set of parameters that represents path functions, is: i) q + w ii) q iii) w iv) H −TS (1) (ii) and (iii) (2) (i), (ii), and (iii) (3) (ii), (iii) and (iv) (4) (i) and (iv)

Q37.Consider the following statements (a) The pH of a mixture containing 400 mL of 0.1 M H2SO4 and 400 mL of 0.1 M NaOH will be approximately 1.3. (b) Ionic product of water is temperature dependent. (c) A monobasic acid with Ka = 10−5 has a pH = 5 . The degree of dissociation of this acid is 50% . (d) The Le Chatelier's principle is not applicable to common-ion effect. The correct statements are: (1) (b) and (c) (2) (a), (b) and (d) (3) (a) and (b) (4) (a), (b) and (c)

Q37.What is the molar solubility of AIOH3 in 0.2 M NaOH solution? Given that, solubility product of AlOH3 = 2.4 × 10-24 : (1) 3 × 10-19 (2) 12 × 10-21 (3) 12 × 10-23 (4) 3 × 10-22

Q37.The number of 2 -centre- 2 -electron and 3 -centre- 2 -electron bonds in B2H6 , respectively, are: (1) 4 and 2 (2) 2 and 4 (3) 2 and 2 (4) 2 and 1 JEE Main 2019 (10 Jan Shift 2) JEE Main Previous Year Paper

Q37.The metal that forms nitride by reacting directly with N2 of air is: (1) Li (2) Rb (3) Cs (4) K

Q37.Given that, EO2o / H2O = + 1 .23 V; o ES2O82 - / SO42 - = 2 .05 V EBr2o / Br- = + 1 . 09 V; = 1 .4 V EAu3o + / Au The strongest oxidizing agent is (1) O2 (2) S2O82 - (3) Br2 (4) Au3 + Q38.100 mL of a water sample contains 0.81 g of calcium bicarbonate and 0.73 g of magnesium bicarbonate. The hardness of this water sample expressed in terms of equivalents of CaCO3 is: (molar mass of calcium bicarbonate is 162 gm mol-1 and magnesium bicarbonate is 146 g mol-1 ) (1) 100 ppm (2) 1,000 ppm (3) 5,000 ppm (4) 10,000 ppm

Q37.Match the following items in column I with the corresponding items in column II. (1) (i) → (B); (ii) → (C); (iii) → (A); (iv) → (D) (2) (i) →(C); (ii) →(B); (iii) →(D); (iv) →(A) (3) (i) → (D); (ii) → (A); (iii) → (B); (iv) → (C) (4) (i) → (C); (ii) → (D); (iii) → (B); (iv) → (A)

Q37.The temporary hardness of a water sample is due to compound X. Boiling this sample converts X to compound Y. X and Y, respectively, are: (1) Mg(HCO3)2 and MgCO3 (2) Ca(HCO3)2 and Ca(OH)2 (3) Mg(HCO3)2 and Mg(OH)2 (4) Ca(HCO3)2 and CaO

Q37.The chemical nature of hydrogen peroxide is: (1) Oxidizing and reducing agent in both acidic and (2) Oxidizing agent in acidic medium, but not in basic medium. basic medium (3) Oxidizing and reducing agent in acidic medium, (4) Reducing agent in basic medium, but not in but not in basic medium acidic medium.

Q37.The amphoteric hydroxide is: (1) Be(OH)2 (2) Ca(OH)2 (3) Mg(OH)2 (4) Sr(OH)

Q37.Given: (i) C(graphite) + O2(g) →CO2(g); ΔrHΘ = x kJ mol−1 (ii) C(graphite) + 12 O2(g) →CO(g) ; ΔrHΘ = y kJ mol−1 (iii) CO(g) + 12 O2(g) →CO2(g); ΔrHΘ = z kJ mol−1 Based on the above thermochemical equations, find out which one of the following algebraic relationships is correct? (1) x = y + z (2) z = x + y (3) y = 2z −x (4) x = y −z

Q37.Two solids dissociate as follows: A (s) ⇌B (g) + C (g); KP1 = x atm2 D (s) ⇌C (g) + E (g); KP2 = y atm2 The total pressure when both the solids dissociate simultaneously is: (1) √x + y atm (2) x2 + y2 atm (3) (x + y) atm (4) 2(√x + y) atm Q38. 50 mL of 0 .5 M oxalic acid is needed to neutralize 25 mL of sodium hydroxide solution. What is the amount of NaOH in 50 mL of the given sodium hydroxide solution? (1) 2 g (2) 4 g (3) 1 g (4) 8 g

Q37.The structures of beryllium chloride in the solid state and vapour phase, respectively, are: (1) chain and chain (2) dimeric and chain (3) chain and dimeric (4) dimeric and dimeric

Q37.The pH of a 0.02 M NH4Cl solution will be [Given: KbNH4OH = 10-5 and log⁡2 = 0.301] (1) 4.65 (2) 2.65 (3) 4.35 (4) 5.35

Q37.For the following reaction, equilibrium constant are given: Ss + O2g ⇌SO2g; K1 = 1052 2Ss + 3O2g ⇌2SO3g; K2 = 10129 The equilibrium constant for the reaction, 2SO2g + O2g ⇌2SO3g is: (1) 10154 (2) 1025 (3) 10181 (4) 1077