Practice Questions

Q36.The number of sp2 hybrid orbitals in a molecule of benzene is: (1) 24 (2) 6 (3) 18 (4) 12

Q36.Complex A has a composition of H12O6 Cl3 Cr. If the complex on treatment with conc. H2 SO4 loses 13. 5% of its original mass, the correct molecular formulas of A is: [Given : atomic mass of Cr = 52 amu and CI = 35 amu] (1) [Cr(H2O6] Cl3 (2) [Cr (H2O)3 Cl3] ⋅3H2O (3) [Cr (H2O)5 Cl] Cl2 ⋅H2O (4) [Cr (H2O)4 Cl2]Cl ⋅2H2O

Q36.The major product (Y) in the following reactions is: JEE Main 2020 (09 Jan Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q36.For the reaction 2H2(g) + 2NO(g) →N2(g) + 2H2O(g) the observed rate expression is, rate = kf[NO]2[H2] . The rate expression for the reverse reaction is: (1) kb[N2][H2O]2 (2) kb[N2][H2O]2/[NO] (3) kb[N2][H2O] (4) kb[N2][H2O]2/[H2]

Q36.For the equilibrium A ⇌B , the variation of the rate of the forward (a) and reverse (b) reaction with time is given by: JEE Main 2020 (04 Sep Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q36.The results given in the below table were obtained during kinetic studies of the following reaction: 2A + B →C + D Experiment [A]/ molL−1 [B]/ molL−1 Initial rate/ molL−1 min−1 I 0. 1 0. 1 6. 00 × 10−3 II 0. 1 0. 2 2. 40 × 10−2 III 0. 2 0. 1 1. 20 × 10−2 IV X 0. 2 7. 20 × 10−2 V 0. 3 Y 2. 88 × 10−1 X and Y in the given table are respectively : (1) 0. 4, 0. 4 (2) 0. 4, 0. 3 (3) 0. 3, 0. 4 (4) 0. 3, 0. 3

Q36.At 35 oC, the vapour pressure of CS2, is 512mm Hg and that of acetone is 144 mmHg. A solution of CS2 in acetone has a total vapour pressure of 600 mmHg . The false statement amongst the following is: JEE Main 2020 (07 Jan Shift 1) JEE Main Previous Year Paper (1) Raoult's law is not obeyed by this system (2) a mixture of 100mLCS2 and 100mL acetone has a volume < 200mL (3) CS2 and acetone are less attracted to each other (4) heat must be absorbed in order to produce the than to themselves solution at 35oC

Q36.A graph of vapour pressure and temperature for three different liquids X, Y and Z is shown below: The following inferences are made: (A)X has higher intermolecular interactions compared to Y. (B)X has lower intermolecular interactions compared to Y. (C)Z has lower intermolecular interactions compared to Y. The correct inferences is/are: JEE Main 2020 (08 Jan Shift 1) JEE Main Previous Year Paper (1) (A) and (C) (2) (A) (3) (B) (4) (C)

Q36.The increasing order of the following compounds towards HCN addition is : (i) (ii) (iii) (iv) (1) (i) < (iii) < (iv) < (ii) (2) (iii) < (iv) < (i) < (ii) (3) (iii) < (i) < (iv) < (ii) (4) (iii) < (iv) < (ii) < (i)

Q36.Consider the following reactions A →P1; B →P2; C →P3; D →P4 JEE Main 2020 (06 Sep Shift 1) JEE Main Previous Year Paper The order of the above reactions are a, b, c and d,respectively. The following graph is obtained when log[rate] vs.log[conc.] are plotted: Among the following, the correct sequence for the order of the reactions is : (1) d > a > b > c (2) a > b > c > d (3) c > a > b > d (4) d > b > a > c

Q36.Which of the following compounds is likely to show both Frenkel and Schottky defects in its crystalline form? (1) AgBr (2) CsCl (3) KBr (4) ZnS JEE Main 2020 (08 Jan Shift 2) JEE Main Previous Year Paper

Q36.Let CNaCl and CBaSO4 , be the conductances (in S) measured for saturated aqueous solutions of NaCl and BaSO4 respectively, at a temperature T. Which of the following is false? (1) lonic mobilities of ions from both salts increase with T. (2) CBaSO4(T2) > CBaSO4(T1) for T2 > T1 (3) CNaCl(T2) > CNaCl(T1) for T2 > T1 (4) CNaCl ≫CBaSO4 at given T

Q36.The element that can be refined by distillation is : (1) nickel (2) zinc (3) tin (4) gallium

Q36.An element crystallises in a face–centred cubic (fcc) unit cell with cell edge a. The distance between the centres of two nearest octahedral voids in the crystal lattice is: (1) a (2) a √2 (3) √2a (4) a2

Q36.Identify the correct molecular picture showing what happens at the critical micellar concentration (CMC) of an aqueous solution of a surfactant (1) (D) (2) (B) (3) (A) (4) (C)

Q37.Match the following: (i) Foam (a) smoke (ii) Gel (b) cell fluid (iii) Aerosol (c) jellies (iv) Emulsion (d) rubber (e) froth (f) milk (1) (i) – (b), (ii) – (c), (iii) – (e), (iv) – (d) (2) (i) – (d), (ii) – (b), (iii) – (a), (iv) – (e) (3) (i) – (e), (ii) – (c), (iii) – (a), (iv) – (f) (4) (i) – (d), (ii) – (b), (iii) – (e), (iv) – (f)

Q37.Amongst the following statements regarding adsorption, those that are valid are: (a) ΔH becomes less negative as adsorption proceeds. (b) On a given adsorbent, ammonia is adsorbed more than nitrogen gas. (c) On adsorption, the residual force acting along the surface of the adsorbent increases (d) With increase in temperature, the equilibrium concentration of adsorbate increases. (1) (d) and (a) (2) (b) and (c) (3) (a) and (b) (4) (c) and (d)

Q37.Biochemical Oxygen Demand (BOD) is the amount of oxygen required (in ppm ): (1) for sustaining life in a water body. (2) by bacteria to break-down organic waste in a certain volume of a water sample. (3) for the photochemical breakdown of waste present in 1m3 volume of a water body (4) by anaerobic bacteria to breakdown. inorganic waste present in a water body.

Q37.The d-electron configuration of [Ru(en)3] Cl2 , and [Fe (H2O)6] Cl2 respectively are: (1) t62ge0g and t62ge0g (2) t42ge2g and t62ge0g (3) t62ge0g and t42ge2g (4) t42ge2g and t42ge2g

Q37.For the following reactions 700K −A → Product 500K −A → Product catalyst It was found that the Ea is decreased by 30 KJ/mol in the presence of catalyst. If the rate remains unchanged, the activation energy for catalysed reaction is (Assume pre-exponential factor is same) (1) 75 KJ/mol (2) 105 KJ/mol (3) 135 KJ/mol (4) 198 KJ/mol

Q37.The refining method used when the metal and the impurities have low and high melting temperatures, respectively, is (1) liquation. (2) vapour phase refining. (3) zone refining. (4) distillation.

Q37.Given that the standard potentials (Eo) of Cu2+ / Cu and Cu+ / Cu are 0.34V and 0.522V respectively, the Eo of Cu2+ / Cu+ is: (1) 0.182V (2) +0.158V (3) −0.182V (4) −0.158V

Q37.The rate of a certain biochemical reaction at physiological temperature (T) occurs 106 times faster with enzyme than without. The change in the activation energy upon adding enzyme is: (1) −6(2.303)RT (2) −6RT (3) +6(2.303)RT (4) +6RT

Q37.The variation of molar conductively with concentration of an electrolyte (X) in aqueous solution is shown in the given figure. The electrolyte X is : (1) HCl (2) NaCl (3) KNO3 (4) CH3 COOH

Q37.Kraft temperature is the temperature: (1) below which the aqueous solution of detergents starts freezing. (2) below which the formation of micelles takes place. (3) above which the aqueous solution of detergents starts boiling. (4) above which the formation of micelles takes place.