Practice Questions

Q37.In reaction A + 2 B ⇌2C + D, initial concentration of B was 1.5 times of [A], but at equilibrium the concentrations of A and B became equal. The equilibrium constant for the reaction is : (1) 8 (2) 4 (3) 12 (4) 6

Q37.In which of the following sets, all the given species are isostructural ? (1) CO2, NO2, ClO2, SiO2 (2) PCl3, AlCl3, BCl3, SbCl3 (3) BF3, NF3, PF3, AlF3 (4) BF−4 , CCl4, NH+4 , PCl+4

Q37.Which of the following statements/relationships is not correct in thermodynamic changes ? (1) ΔU = 0 (isothermal reversible expansion of a (2) w = −nRT ln V2 (isothermal reversible V1 gas) expansion of an ideal gas) (3) w = nRT ln V2 (isothermal reversible (4) For a system of constant volume heat involved V1 expansion of an ideal gas) directly changes to internal energy.

Q38.Which one of the following arrangements represents the correct order of solubilities of sparingly soluble salts Hg2Cl2, Cr2(SO4)3 , BaSO4 and CrCl3 respectively? (1) BaSO4 > Hg2Cl2 > Cr2(SO4)3 > CrCl3 (2) BaSO4 > Hg2Cl2 > CrCl3 > Cr2(SO4)3 (3) BaSO4 > CrCl3 > Hg2Cl2 > Cr2(SO4)3 (4) Hg2Cl2 > BaSO4 > CrCl3 > Cr2(SO4)3

Q38.Stability of the species Li2, Li−2 and Li+2 increases in the order of (1) Li2 < Li−2 < Li+2 (2) Li−2 < Li2 < Li+2 (3) Li2 < Li+2 < Li−2 (4) Li−2 < Li+2 < Li2

Q38.Solid Ba(NO3)2 is gradually dissolved in a 1.0 × 10−4 M Na2CO3 solution. At which concentration of Ba2+ , precipitate of BaCO3 begins to form ? (Ksp for BaCO3 = 5.1 × 10−9) (1) 5.1 × 10−5M (2) 7.1 × 10−8M (3) 4.1 × 10−5M (4) 8.1 × 10−7M

Q38.The internuclear distances in O −O bonds for O+2 , O2, O−2 and O2−2 respectively are : (1) 1.30 Å, 1.49 Å, 1.12 Å, 1.21 Å (2) 1.49 Å, 1.21 Å, 1.12 Å, 1.30 Å (3) 1.21 Å, 1.12 Å, 1.49 Å, 1.30 Å (4) 1.12 Å, 1.21 Å, 1.30 Å, 1.49 Å

Q38.(1) N2( g) + 3H2( g) ⇌2NH3( g), K1 (2) N2( g) + O2( g) ⇌2NO(g), K2 (3) H2( g) + 12 O2( g) ⇌H2O(g), K3 The equation for the equilibrium constant of the reaction 5 2NH3( g) + O2( g) ⇌2NO(g) + 3H2O(g), 2 (K4) in terms of K1, K2 and K3 is : (1) K1⋅K2 (2) K1⋅K23 K3 K2 3 (3) K1 K2 K3 (4) K2⋅K3 K1

Q39.Which one of the following molecules is expected to exhibit paramagnetic behaviour? (1) O2 (2) O2 -2 (3) C2 (4) N2

Q39.Given : XNa2HAsO3 + YNaBrO3 + ZHCl →NaBr + H3AsO4 + NaCl The values of X, Y and Z in the above redox reaction are respectively : (1) 2, 1, 2 (2) 2, 1, 3 (3) 3, 1, 6 (4) 3, 1, 4

Q39.The structure of which of the following chloro species can be explained on the basis of dsp2 hybridization? (1) PdCl2−4 (2) FeCl2−4 (3) CoCl2−4 (4) NiCl2−4

Q39. NaOH is a strong base. What will be pH of 5.0 × 10−2MNaOH solution ? (log 2 = 0.3) (1) 14.00 (2) 13.70 (3) 13.00 (4) 12.70

Q39.What is the pH of a 10−4MOH− solution at 330 K, if Kw at 330 K is 10−13.6 ? (1) 4 (2) 9.0 (3) 10 (4) 9.6

Q40.In which of the following pairs of molecules/ions, both the species are not likely to exist? (1) H2+2 , He2 (2) H−2 , He2+2 (3) H+2 , He2−2 (4) H−2 , He2−2 ¯

Q40.Sodium Carbonate cannot be used in place of (NH4)2CO3 for the identification of Ca2+, Ba2+ and Sr2+ ions (in group V ) during mixture analysis because : (1) Mg2+ ions will also be precipitated. (2) Concentration of CO32− ions is very low. (3) Sodium ions will react with acid radicals. (4) Na+ ions will interfere with the detection of Ca2+, Ba2+, Sr2+ ions.

Q40.Which one of the following is the wrong assumption of kinetic theory of gases ? JEE Main 2013 (25 Apr Online) JEE Main Previous Year Paper (1) Momentum and energy always remain conserved.(2) Pressure is the result of elastic collision of molecules with the container's wall. (3) Molecules are separated by great distances (4) All the molecules move in straight line between compared to their sizes. collision and with same velocity.

Q40.The numbers of protons, electrons and neutrons in a molecule of heavy water are respectively : (1) 8, 10, 11 (2) 10, 10, 10 (3) 10, 11, 10 (4) 11, 10, 10 JEE Main 2013 (23 Apr Online) JEE Main Previous Year Paper

Q40. Acid Ka HCN 6.2 × 10−10 Values of dissociation constant, Ka are given as follows : Correct order of increasing HF 7.2 × 10−4 HNO2 4.0 × 10−4 base strength of the base CN−, F− and NO−2 will be : (1) F−< CN−< NO−2 (2) NO−2 < CN−< F− (3) F−< NO−2 < CN− (4) NO−2 < F−< CN−

Q41.For which of the following compounds Kjeldahl method can be used to determine the percentage of Nitrogen? (1) Nitrobenzene (2) Pyridine (3) Alanine (4) Diazomethane JEE Main 2013 (22 Apr Online) JEE Main Previous Year Paper

Q41.For gaseous state, if most probable speed is denoted by C* , average speed by C and root mean square speed by C, then for many molecules, what is the ratios of these speeds? (1) − (2) − C* : C : C = 1 : 1 .128 : 1 .225 C* : C : C = 1 : 1 .225 : 1 .128 (3) − (4) − C* : C : C = 1 .225 : 1 .128 : 1 C* : C : C = 1 .128 : 1 .225 : 1

Q41.Which one of the following is most stable ? JEE Main 2013 (09 Apr Online) JEE Main Previous Year Paper (1) (2) (3) (4)

Q41.In which of the following exothermic reactions, the heat liberated per mole is the highest ? (1) CaO + H2O →Ca(OH)2 (2) SrO + H2O →Sr(OH)2 (3) BaO + H2O →Ba(OH)2 (4) MgO + H2O →Mg(OH)2

Q41.Equimolar solutions of the following compounds are prepared separately in water. Which will have the lowest pH value ? (1) BeCl2 (2) SrCl2 (3) CaCl2 (4) MgCl2

Q42.Rate of dehydration of alcohols follows the order: (1) 2∘> 1∘> CH3OH > 3∘ (2) 3∘> 2∘> 1∘> CH3OH (3) 2∘> 3∘> 1∘> CH3OH (4) CH3OH > 1∘> 2∘> 3∘

Q42.A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 37. 0∘C. As it does so, it absorbs 208 J of heat. The values of q and w for the process will be (R = 8.314 J/mol K) (ln7.5 = 2.01) (1) q = −208 J, w = +208 J (2) q = +208 J, w = +208 J (3) q = +208 J, w = −208 J (4) q = −208 J, w = −208 J