Practice Questions

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.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 IUPAC name for the following compound is : (1) 2, 5 -dimenthyl- 5 -carboxy-hex- 3-enal (2) 2, 5 -dimenthyl- 6 -carboxy-hex- 3-enal (3) 2, 5 -dimenthyl- 6 -carboxy-hex- 3-enoic acid (4) 6-formyl- 2 -methy 1 -hex- 3 -enoic acid

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 reaction of NO with N2O4 at 250 K gives : (1) N2O (2) NO2 (3) N2O3 (4) N2O5

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

Q38.The incorrect statement(s) among (a) - (c) is (are) : (a) W(VI) is more stable than Cr(VI). (b) in the presence of HCl, permanganate titrations provide satisfactory results. JEE Main 2020 (04 Sep Shift 2) JEE Main Previous Year Paper (c) some lanthanoid oxides can be used as phosphors (1) (b) and (c) only (2) (a) and (b) only (3) (b) only (4) (a) only

Q38.In the following reactions, products (A) and (B) , respectively, are: NaOH + Cl2 →(A) + side products (hot and conc. ) Ca(OH)2 + Cl2 →(B) + side products (dry) (1) NaClO3 and Ca(OCl)2 (2) NaClO3 and Ca(ClO3)2 (3) NaOCl and Ca(OCl)2 (4) NaOCl and Ca(ClO3)2

Q38.According to the following diagram, A reduces BO2 when the temperature is: (1) < 1400oC (2) > 1400oC (3) > 1200oC but < 1400oC (4) < 1200oC

Q38.Reaction of an inorganic sulphite X with dilute H2 SO4 generated compound Y . Reaction of Y with NaOH gives X . Further, the reaction of X with Y and water affords compound Z, Y and X , respectively, are : (1) SO2 and Na2 SO3 (2) SO3 and NaHSO3 (3) SO2 and NaHSO3 (4) S and Na2 SO3

Q38.Amongst the following, the form of water with the lowest ionic conductance at 298K is: (1) distilled water (2) saline water used for intravenous injection (3) water from a well (4) sea water

Q38.The structure of PCl5 in the solid state is : (1) tetrahedral [PC4]+ and octahedral [PCl6]− (2) square planar [PCl4]+ and octahedral [PCl6]− (3) square pyramidal (4) trigonal bipyramidal

Q38.The major product in the following reaction is: (1) (2) (3) (4)

Q38.The decreasing order of reactivity of the following compounds towards nucleophilic substitution ( SN2 ) is: (1) (II) > (III) > (I) > (IV) (2) (II) > (III) > (IV) > (I) (3) (III) > (II) > (IV) > (I) (4) (IV) > (II) > (III) > (I)

Q38.The rate constant (k) of a reaction is measured at different temperature (T), and the data are plotted in the given figure. the activation energy of the reaction in kJmol−1 is : (R is gas constant) JEE Main 2020 (05 Sep Shift 2) JEE Main Previous Year Paper (1) 2/R (2) 1/R (3) R (4) 2R

Q38.Tyndall effect is observed when : (1) The diameter of dispersed particles is much (2) The diameter of dispersed particles is much larger than the wavelength of light used. smaller than the wavelength of light used (3) The refractive index od dispersed phase is greater (4) The diameter of dispersed particles is similar to than that of the dispersion medium. the wavelength of light used.

Q38.The purest form of commercial iron is: (1) pig iron (2) wrought iron (3) cast iron (4) scrap iron and pig iron

Q38.Cast iron is used for the manufacture of : (1) wrought iron and pig iron (2) pig iron, scrap iron and steel (3) wrought iron, pig iron and steel (4) wrought iron and steel

Q38.Among statements (a) – (d), the correct ones are : (a) Lime stone is decomposed to CaO during the extraction of iron from its oxides. (b) In the extraction of silver, silver is extracted as an anionic complex. (c) Nickel is purified by Mond’s process. (d) Zr and Ti are purified by Van Arkel method. (1) (a), (b), (c) and (d) (2) (a), (c) and (d) only (3) (b), (c) and (d) only (4) (c) and (d) only

Q38.The correct statement with respect to dinitrogen is: (1) N2 is paramagnetic in nature. (2) it can combine with dioxygen at 25°C (3) liquid dinitrogen is not used in cryosurgery. (4) it can be used as an inert diluent for reactive chemicals

Q38.The major product in the following reaction is : JEE Main 2020 (02 Sep Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q38.As per Hardy-Schulze formulation, the flocculation values of the following for ferric hydroxide sol are in the order: (1) K3[Fe(CN)6] < K2CrO4 < KBr = KNO3 = AlCl3K3[Fe(CN)6](2) < K2CrO4 < AlCl3 < KBr < KNO3 (3) AlCl3 > K3[Fe(CN)6] > K2CrO4 > KBr = KNO3K3[Fe(CN)6](4) > AlCl3 > K2CrO4 > KBr > KNO3

Q39.The presence of soluble fluoride ion upto 1 ppm concentration in drinking water, is : (1) harmful for teeth (2) harmful to skin (3) harmful to bones (4) safe for teeth

Q39.The number of possible optical isomers for the complexes MA2B2 with sp3 and dsp2 hybridized metal atom, respectively, is: Note: A and B are unidentate neutral and unidentate monoanionic ligands, respectively. (1) 0 and 2 (2) 2 and 2 (3) 0 and 0 (4) 0 and 1

Q39.The correct order of the spin-only magnetic moments of the following complexes is: (I) [Cr(H2O)6]Br2 (II) Na4[Fe(CN)6] (III) Na3[Fe(C2O4)3](Δ0 > P) (IV) (Et4N)2[CoCl4] (1) (III) > (I) > (IV) > (II) (2) (III) > (I) > (II) > (IV) (3) (I) > (IV) > (III) > (II) (4) (II) ≈(I) > (IV) > (III)