Practice Questions

Q53.The spin-only magnetic moment value of B2+ species is × 10-2BM (Nearest integer) [ Given : √3 = 1 . 73]

Q53.A certain orbital has n = 4 and ml = −3. The number of radial nodes in this orbital is _______. (Round off to the Nearest Integer).

Q54.A system does 200 J of work and at the same time absorbs 150 J of heat. The magnitude of the change in internal energy is ______ J. (Nearest integer)

Q54.Among the following, number of metal/s which can be used as electrodes in the photoelectric cell is ___ . (Integer answer) JEE Main 2021 (25 Feb Shift 2) JEE Main Previous Year Paper (A) Li (B) Na (C) Rb (D) Cs

Q54.Assuming ideal behaviour, the magnitude of log K for the following reaction at 25°C is x × 10−1. The value of x is __________. (Integer answer) 3HC ≡CH(g) ⇌C6H6(l) [Given: ΔfG°(HC ≡CH) = −2. 04 × 105 J mol−1; ΔfG°(C6H6) = −1. 24 × 105 J mol−1; R = 8. 314 J K−1 mol−1 ]

Q54.At 298 K, the enthalpy of fusion of a solid X is 2 . 8 kJ mol-1 and the enthalpy of vaporisation of the liquid X is 98 . 2 kJ mol-1. The enthalpy of sublimation of the substance X in kJ mol-1 is ______. (in nearest integer)

Q55.The ratio of number of water molecules in Mohr's salt and potash alum is ×10−1. (Integer answer)

Q55.The molarity of the solution prepared by dissolving 6. 3 g of oxalic acid (H2C2O4 ⋅2H2O) in 250 mL of water in mol L−1 is x × 10−2. The value of x is _________ . (Nearest integer) [Atomic mass : H : 1. 0, C : 12. 0, 0 : 16. 0 J]

Q55.For the reaction 2NO2 ( 𝑔) ⇌N2O4 ( g ) , when ΔS = - 176 . 0 J K-1 and ΔH = - 57 . 8 kJ mol-1 the magnitude of ΔG at 298 K for the reaction is _____ kJmol-1. (Nearest integer)

Q55.Dichromate ion is treated with base, the oxidation number of Cr in the product formed is Q56. 224 mL of SO2(g) at 298 K and 1 atm is passed through 100 mL of 0. 1 M NaOH solution. The non-volatile solute produced is dissolved in 36 g of water. The lowering of vapour pressure of solution (assuming the solution is dilute) ( P°(H2O)= 24 mm of Hg ) is x × 10−2 mm of Hg the value of x is (Integer answer)

Q55.The empirical formula for a compound with a cubic close packed arrangement of anions and with cations occupying all the octahedral sites in Ax B . The value of x is (Integer answer)

Q56.Sodium oxide reacts with water to produce sodium hydroxide. 20 . 0 g of sodium oxide is dissolved in 500 mL of water. Neglecting the change in volume, the concentration of the resulting NaOH solution is _________ × 10-1M . (Nearest integer) [Atomic mass : Na = 23 . 0, O = 16 . 0, H = 1 . 0] Q57.1 . 22 g of an organic acid is separately dissolved in 100 g of benzene Kb = 2 . 6 K kg mol-1 and 100 g of acetone Kb = 1 . 7 K kg mol-1 . The acid is known to dimerize in benzene but remain as a monomer in acetone. The boiling point of the solution in acetone increases by 0 . 17°C . The increase in boiling point of solution in benzene in∘C is x × 10-2 . The value of x is (Nearest integer) [Atomic mass : C = 12 . 0, H = 1 . 0, O = 16 . 0]

Q56.The dihedral angle in staggered form of Newmann's projection of 1, 1, 1 -Trichloro ethane is … … … degree. (Round off to the nearest integer) (Round off to the nearest integer)

Q57. The number of sigma bonds in is _______.

Q57.Consider the following chemical reaction. 1) Red hot Fe tube, 873 K CH ≡CH 2) CO,HCl,AlCl3 > Product The number of sp2 hybridized carbon atom(s) present in the product is Q58. 1 molal aqueous solution of an electrolyte A2 B3 is 60% ionised. The boiling point of the solution at 1 atm is _____ K. (Rounded-off to the nearest integer) [Given Kb for (H2O) = 0. 52 K kg mol−1 ]

Q57.If the concentration of glucose (C6H12O6) in blood is 0. 72 gL−1, the molarity of glucose in blood is −× 10−3M (Nearest integer): [Given : Atomic mass of C = 12, H = 1, O = 16 u] + 2 Ag(s)

Q57.When 12. 2 g of benzoic acid is dissolved in 100 g of water, the freezing point of solution was found to be −0. 93 °C(Kf(H2O) = 1. 86 K kg mol−1). The number (n) of benzoic acid molecules associated (assuming 100% association) is _.

Q57.If 80 g of copper sulphate CuSO4 · 5H2O is dissolved in deionised water to make 5 L of solution. The concentration of the copper sulphate solution is 𝑥× 10-3 mol 𝐿-1 . The value of 𝑥 is _____. [ Atomic masses Cu : 63 . 54u, S : 32u, O : 16u, H : 1u]

Q57.At 363 K, the vapour pressure of A is 21 kPa and that of B is 18 kPa. One mole of A and 2 moles of B are mixed. Assuming that this solution is ideal, the vapour pressure of the mixture is___________ kPa. (Round of to the Nearest Integer ).

Q58.The coordination number of an atom in a body-centered cubic structure is______ [Assume that the lattice is made up of atoms.]

Q58.An exothermic reaction X →Y has an activation energy 30 kJ mol−1 . If energy change ΔE during the reaction is −20 kJ, then the activation energy for the reverse reaction in kJ is (Integer answer) JEE Main 2021 (26 Feb Shift 1) JEE Main Previous Year Paper Q59. 3. 12 g of oxygen is adsorbed on 1. 2 g of platinum metal. The volume of oxygen adsorbed per gram of the adsorbent at 1 atm and 300 K in L is [R = 0. 0821 L atm K−1 mol−1]

Q58.If the conductivity of mercury at 0°C is 1 . 07 × 106 S m-1 and the resistance of a cell containing mercury is 0 . 243𝛺, then the cell constant of the cell is 𝑥× 104 m-1 . The value of 𝑥 is ______ . (Nearest integer)

Q59.The number of 4f electrons in the ground state electronic configuration of Gd2+ is [Atomic number of Gd = 64]

Q59.When 9 . 45 g of ClCH2COOH is added to 500 mL of water, its freezing point drops by 0 . 5°C . The dissociation constant of ClCH2COOH is 𝑥× 10-3 . The value of x is off to the nearest integer) KfH2O = 1 . 86 K kg mol-1

Q59.In the ground state of atomic Fe(Z = 26), the spin-only magnetic moment is ×10−1 BM. (Round off to the Nearest Integer). [ Given : √3 = 1. 73, √2 = 1. 41]