Practice Questions

Q55.The solubility product of PbI2 is 8. 0 × 10−9. The solubility of lead iodide in 0. 1 molar solution of lead nitrate is x × 10−6 mol /L. The value of x is _________ (Rounded off to the nearest integer) [Given √2 = 1. 41]

Q56.A 1 molal K4 Fe(CN)6 solution has a degree of dissociation of 0. 4 . Its boiling point is equal to that of another solution which contains 18. 1 weight percent of a non electrolytic solute A . The molar mass of A is _____ u. (Round off to the Nearest Integer). [Density of water = 1. 0 g cm−3]

Q56.The vapour pressures of A and B at 25°C are 90 mmHg and 15 mm Hg respectively. If A and B are mixed such that the mole fraction of A in the mixture is 0. 6, then the mole fraction of B in the vapour phase is x × 10−1. The value of x is (Nearest integer)

Q56. Ga (atomic mass 70 u ) crystallizes in a hexagonal close packed structure. The total number of voids in 0. 581 g of Ga is ________ ×1021 . (Round off to the Nearest Integer).

Q56. C6H6 freezes at 5. 5°C. The temperature at which a solution of 10 g of C4H10 in 200 g of C6H6 freeze is _______ ∘C. (nearest integer value), (The molal freezing point depression constant of C6H6 is 5. 12°C/m.)

Q56.Of the following four aqueous solutions, the total number of those solutions whose freezing point is lower than that of 0. 10 MC2 H5 OH is (Integer answer) (i) 0. 10M Ba3 (PO4)2 (ii) 0. 10M Na2 SO4 (iii) 0. 10M KCl (iv) 0. 10M Li3 PO4

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.The molar solubility of Zn ( OH ) in 0 . 1MNaOH solution is 𝑥× 10-18M . The value of 𝑥 is _____ . (Nearest 2 integer) Given : The solubility product of Zn(OH ) is 2 × 10-20 2

Q56.Using the provided information in the following paper chromatogram: JEE Main 2021 (25 Feb Shift 1) JEE Main Previous Year Paper The calculated Rf value of A is _____ × 10−1 .

Q56.An organic compound is subjected to chlorination to get compound A using 5. 0 g of chlorine. When 0. 5 g of compound A is reacted with AgNO3 [Carius Method], the percentage of chlorine in compound A is when it forms 0. 3849 g of AgCl. (Round off to the Nearest Integer) (Atomic masses of Ag and Cl are 107. 87 and 35. 5 respectively) Q57. 1. 46 g of a biopolymer dissolved in a 100 mL water at 300 K exerted an osmotic pressure of 2. 42 × 10−3 bar The molar mass of the biopolymer is −× 104 g mol−1. (Round off to the Nearest Integer) [Use: R = 0. 083 L bar mol−1 K−1]

Q56.The number of octahedral voids per lattice site in a lattice is_. (Rounded off to the nearest integer)

Q56.A chloro compound "A". (i) forms aldehydes on ozonolysis followed by the hydrolysis. (ii) when vaporized completely 1. 53 g of A, gives 448 mL of vapour at STP. The number of carbon atoms in a molecule of compound A is Q57. 83 g of ethylene glycol dissolved in 625 g of water. The freezing point of the solution is ..... K. (Nearest integer) [Use : Molal Freezing point depression constant of water = 1. 86 K kg mol−1 Freezing point of water = 273 K Atomic masses : C : 12. 0u, O : 16. 0u, H : 1. 0u]

Q56.A solute A dimerizes in water. The boiling point of a 2 molal solution of A is 100. 52∘C. The percentage association of A is ___ . (Round off to the Nearest integer) Use : Kb for water = 0. 52 K kg mol−1 Boiling point of water = 100°C

Q56.At 20°C, the vapour pressure of benzene is 70 torr and that of methyl benzene is 20 torr. The mole fraction of benzene in the vapour phase at 20°C above an equimolar mixture of benzene and methyl benzene is __ × 10−2. (Nearest integer)

Q56.When 5. 1 g of solid NH4 HS is introduced into a two litre evacuated flask at 27°C, 20% of the solid decomposes into gaseous ammonia and hydrogen sulphide. The Kp for the reaction at 27°C is x × 10−2 . The JEE Main 2021 (27 Aug Shift 2) JEE Main Previous Year Paper value of x is (Integer answer) [Given 1R = 0. 082 L atm K−1 mol−1] Q57. 40 g of glucose (Molar mass = 180) is mixed with 200 mL of water. The freezing point of solution is __K. (Nearest integer) [Given : Kf = 1. 86 K kg mol−1; Density of water = 1. 00 g cm−3; Freezing point of water = 273. 15 K]

Q56.Consider the following cell reaction Cd(s) + Hg2 SO4( s) + 95 H2O(l) ⇌CdSO4 ⋅95 H2O(s) + 2 Hg(l). The value of E0cell is 4. 315 V at 25°C. If ΔH°= −825. 2 kJ mol−1, the standard entropy change ΔS° in J K−1 is _________ . (Nearest integer) [Given : Faraday constant = 96487 C mol−1 ]

Q56.A copper complex crystallising in a CCP lattice with a cell edge of 0. 4518 nm has been revealed by employing X -ray diffraction studies. The density of a copper complex is found to be 7. 62 g cm−3. The molar mass of copper complex is gmol−1 (Nearest integer): [ Given : NA = 6. 022 × 1023 mol−1]

Q56.If a compound AB dissociates to the extent of 75% in an aqueous solution, the molality of the solution which shows a 2. 5 K rise in the boiling point of the solution is ___ molal. (Rounded-off to the nearest integer) [Kb = 0. 52K kg mol−1].

Q56.When 10 mL of an aqueous solution of Fe2 + ions was titrated in the presence of dil H2SO4 using diphenylamine indicator, 15 mL of 0 . 02 M solution of K2Cr2O7 was required to get the end point. The molarity of the solution containing Fe2 + ions is x × 10-2 M. The value of x is ______. (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]

Q56.The number of moles of CuO, that will be utilized in Dumas method for estimating nitrogen in a sample of 57. 5 g of N, N− dimethylaminopentane is ________ ×10−2. (Nearest integer) Q57. 200 mL of 0. 2 M HCl is mixed with 300 mL of 0. 1 M NaOH. The molar heat of neutralization of this reaction is −57. 1 kJ. The increase in temperature in ∘C of the system on mixing is x × 10−2. The value of x is (Nearest integer) [Given: Specific heat of water = 4. 18 J g−1 K−1 JEE Main 2021 (27 Aug Shift 1) JEE Main Previous Year Paper Density of water = 1. 00 g cm−3 ] (Assume no volume change on mixing)

Q56.The reaction of sulphur in alkaline medium is given below: S8s + a OHaq−→b Saq2 −+ c S2O3aq2 −+ d H2Ol The values of '𝑎' is______ (Integer answer)

Q57.The molar conductivity at infinite dilution of barium chloride, sulphuric arid and hydrochloric acid are 280, 860 426 Scm2 mol−1 respectively. The molar conductivity at infinite dilution of barium sulphate is ___ Scm2 mol−1 ( Round off to the Nearest Integer).

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.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 ]