Practice Questions

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

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]

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 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.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.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 ).

Q57. The number of sigma bonds in is _______.

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 _.

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.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]

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.For a chemical reaction A →B , it was found that concentration of B is increased by 0. 2 mol L−1 in 30 min. The average rate of the reaction is ________ ×10−1 mol L−1 h−1 . (in nearest integer)

Q59.The spin only magnetic moment of a divalent ion in aqueous solution (atomic number 29) is ___ BM.

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

Q60.Number of bridging CO ligands in [Mn2 (CO)10] is

Q60.A peptide synthesized by the reactions of one molecule each of Glycine, Leucine, Aspartic acid and Histidine will have _____ peptide linkages.

Q60.The number of compound/s given below which contain/s −COOH group is ___ . (Integer answer) (A) Sulphanilic acid (B) Picric acid (C) Aspirin (D) Ascorbic acid

Q61.If (√3 + + + √3 = 0 1)x + √3 = 0 (2) x2 + (√3 1)x (1) x2 −(√3 = 0 = 0 (4) x2 −(√3 −1)x −√3 (3) x2 + (√3 −1)x −√3

Q62.The probability of selecting integers a ∈[−5, 30] such that x2 + 2 (a + 4) x −5a + 64 > 0 , for all x ∈R, is: (1) 7 (2) 2 36 9 (3) 1 (4) 1 6 4 JEE Main 2021 (20 Jul Shift 1) JEE Main Previous Year Paper

Q26.Preparation of Bakelite proceeds via reactions: (1) Electrophilic addition and dehydration (2) Condensation and elimination (3) Electrophilic substitution and dehydration (4) Nucleophilic addition and dehydration

Q26.The atomic number of the element unnilennium is : (1) 109 (2) 102 (3) 108 (4) 119