Practice Questions

Q35.A flask contains a mixture of compounds A and B. Both compounds decompose by first-order kinetics. The half-lives for A and B are 300 s and 180 s, respectively. If the concentrations of A and B are equal initially, the time required for the concentration of A to be four times that of B (in s) is : (Use ln 2 = 0. 693) (1) 180 (2) 900 (3) 300 (4) 120

Q35.The major product formed in the following reaction is : HBr −CH2 CH = CHCH (CH3)2 → (1) CH3 CH2 CH(Br) CH (CH3)2 (2) CH3 CH(Br) CH2 CH (CH3)2 (3) Br (CH2)3 CH (CH3)2 (4) CH3 CH2 CH2 C(Br)(CH3)2

Q35.The incorrect statement is: (1) Manganate and permanganate ions are tetrahedral (2) In manganate and permanganate ions, the π -bonding takes place by overlap of p-orbitals of oxygen and d- orbitals of maganese (3) Manganate and permanganate ions are paramagnetic (4) Manganate ion is green in colour and permanganate ion is purple in colour

Q35.Henry's constant (in kbar) for four gases α, β, γ and δ in water at 298 K is given below : α β γ δ KH 50 2 2 × 10−5 0. 5 (density of water = 103 k gm−3 at 298 K ) This table implies that : (1) α has the highest solubility in water at a given pressure (2) solubility of γ at 308K is lower than at 298K (3) The pressure of a 55. 5 molal solution of δ is 250 bar (4) The pressure of 55. 5 molal solution of γ is 1 bar.

Q35.The correct order of heat of combustion for following alkadienes is: (1) (a) < (b) < (c) (2) (a) < (c) < (b) (3) (c) < (b) < (a) (4) (b) < (c) < (a)

Q35.The equation that is incorrect is: JEE Main 2020 (07 Jan Shift 2) JEE Main Previous Year Paper (1) (Λ0m)KBr −(Λ0m)NaCl = (Λ0m)KBr −(Λ0m)KCl (2) (Λ0m)KG −(Λ0m)KQ = (Λ0m)NaG −(Λ0m)NaQ (3) (Λ0m)H2O = (Λ0m)HCl + (Λ0m)NaOH −(Λ0m)NaCl (4) (Λ0m)NaBr −(Λ0m)Nal = (Λ0m)KBr −(Λ0m)KI

Q35.Which of the following reactions will not produce a racemic product ? (1) (2) (3) HBr (4)−CH3CH2CH = CH2 →

Q35.Consider the following reactions: conc.H2SO4 −(a) (CH3)3CCH(OH)CH3 → alc.KOH −(b) (CH3)2CHCH(Br)CH3 → (CH3)3O⊖K⊕ −(c) (CH3)2CHCH(Br)CH3 → (d) Which of the reaction(s) will not produce Saytzeff product? (1) (a), (c) and (d) (2) (d) only (3) (c) only (4) (b) and (d)

Q35.The major product of the following reaction is : (1) (2) (3) (4)

Q35. E0 = +0 .34 V Cu2+ Cu E0 = −0 .76 V Zn2+ Zn Identify the incorrect statement from the options below for the above cell: (1) If Eext > 1 .1 V, e– flow from Cu to Zn (2) If Eext > 1 .1 V, Zn dissolves at Zn electrode and Cu deposits at Cu electrode (3) If Eext < 1 .1 V, Zn dissolves at anode and Cu deposits at cathode (4) If Eext = 1 .1 V, no flow of e– or current occurs

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.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.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.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.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.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.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

Q37.Among (a) −(d), the complexes that can show geometrical isomerism are: (a) [Pt(NH3)3Cl]+ (b) [Pt(NH3)Cl5]− (c) [Pt(NH3)2Cl(NO2)] (d) [Pt(NH3)4ClBr]2+ (1) b and c (2) d and a (3) c and d (4) a and b

Q37.A sample of red ink (a colloidal suspension) is prepared by mixing eosine dye, egg white, HCHO and water. The component which ensures stability of the ink sample is : (1) Egg white (2) Water (3) HCHO (4) Eosin dye

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.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.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