Practice Questions

Q34.Which of the following has the shortest C −Cl bond? (1) Cl −CH = CH2 (2) Cl −CH = CH −NO2 (3) Cl −CH = CH −CH3 (4) Cl −CH = CH −OCH3

Q34.Among the following compounds, which one has the shortest C– Cl bond? (1) (2) (3) H3C −Cl (4)

Q34.A flask contains a mixture of isohexane and 3 -methylpentane. One of the liquids boils at 63oC while the other boils at 60oC. What is the best way to separate the two liquids and which one will be distilled out first? (1) fractional distillation, isohexane (2) simple distillation, 3 -methylpentane (3) simple distillation, isohexane (4) fractional distillation, 3 -methylpentane

Q34. The major product of the following reaction is: JEE Main 2020 (02 Sep Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)

Q34.For the reaction 2A + 3B + 32 C →3P , which statement is correct? (1) dnA dt = 32 dnBdt = 34 dnCdt (2) dnAdt = dnBdt = dnCdt (3) dnA dt = 23 dnBdt = 43 dnCdt (4) dnAdt = 23 dnBdt = 34 dnCdt

Q34.Consider the following plots of rate constant versus 1 for four different reactions. Which of the following T orders is correct for the activation energies of these reactions? (1) Eb > Ea > Ed > Ec (2) Ea > Ec > Ed > Eb (3) Ec > Ea > Ed > Eb (4) Eb > Ed > Ec > Ea

Q34.On heating compound (A) gives a gas (B) which is constituent of air. This gas when treated with H2 in the presence of a catalyst gives another gas (C) which is basic in nature. (A) should not be : (1) NaN3 (2) Pb (NO3)2 (3) (NH4)2 Cr2 O7 (4) NH4 NO2

Q34.A set of solutions is prepared using 180 g of water as a solvent and 10 g of different non-volatile solutes A, B and C. The relative lowering of vapour pressure in the presence of these solutes are in the order [Given, molar mass of A = 100 g mol−1 ; B = 200 g mol−1 ; C = 10, 000 g mol−1 ] (1) B > C > A (2) C > B > A (3) A > B > C (4) A > C > B

Q34.A diatomic molecule X2 has a body-centred cubic (bcc) structure with a cell edge of 300 pm. The density of the molecule is 6. 17 gcm−3. The number of molecules present in 200 g of X2 is : (Avogadro constant (NA) = 6 × 1023 mol−1 ) (1) 40 NA (2) 8 NA (3) 4 NA (4) 2 NA

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

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.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 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.Among the gases (a) −(e), the gases that cause greenhouse effect are: (a)CO2 (b)H2O (c)CFCs (d)O2 (e)O3 (1) (a), (b), (c) and (d) (2) (a), (b), (c) and (e) (3) (a) and (d) (4) (a), (c), (d) and (e)

Q35.The processes of calcination and roasting in metallurgical industries, respectively, can lead to : (1) Global warming and photochemical smog (2) Global warming and acid rain (3) Photochemical smog and ozone layer depletion (4) Photochemical smog and global warming Q36. 250 mL of a waste solution obtained from the workshop of a goldsmith contains 0. 1 M AgNO3 and 0. 1M AuCl. The solution was electrolyzed at 2 V by passing a current of 1 A for 15 minutes. The metal/metals electrodeposited will be : (E0Ag+/Ag = 0. 80V, E0Au+/Au = 1. 69V) (1) only gold (2) silver and gold in proportion to their atomic weights (3) only silver (4) silver and gold in equal mass proportion

Q35.In Carius method of estimation of halogen, 0. 172 g of an organic compound showed presence of 0. 08 g of bromine. Which of these is the correct structure of the compound ? JEE Main 2020 (02 Sep Shift 1) JEE Main Previous Year Paper (1) CH3 CHBr2 (2) (3) (4) H3C −CH2 −Br

Q35.The size of a raw mango shrinks to a much smaller size when kept in a concentrated salt solution. Which one of the following process can explain this? (1) Osmosis (2) Dialysis (3) Diffusion (4) Reverse osmosis

Q35.An unsaturated hydrocarbon X absorbs two hydrogen molecules on catalytic hydrogenation, and also gives following reaction: (i)O3 [Ag (NH3)2]+ −−X → A → B (3-oxo-hexanedicarboxylic acid) X will be: (ii) Zn H2O (1) (2) (3) (4)

Q35.For the given cell; Cu(s) Cu2+(C1M) Cu2+(C2M) Cu(s) change in Gibbs energy (ΔG) is negative, it : (1) C1 = C2 (2) C2 = C1 √2 (3) C1 = 2C2 (4) C2 = √2 C1 JEE Main 2020 (06 Sep Shift 2) JEE Main Previous Year Paper

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. 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