Practice Questions

Q57.For a first order reaction, the ratio of the time for 75% completion of a reaction to the time for 50% completion is ___________ . (Integer answer)

Q57.Copper reduces NO−3 into NO and NO2 depending upon the concentration of HNO3 in solution. (Assuming fixed [Cu2+] and PNO = PNO2 ), the HNO3 concentration at which the thermodynamic tendency for reduction of NO−3 into NO and NO2 by copper is same is 10x M. The value of 2x is ___. (Rounded-off to the nearest integer) [Given, Eo = 0. 34 V, Eo = 0. 96 V, Eo = 0. 79 V and at 298 K, RTF (2. 303) = 0. 059] Cu2+ / Cu NO−3 / NO NO−3 / NO2

Q57. The number of sigma bonds in is _______.

Q57.The inactivation rate of a viral preparation is proportional to the amount of virus. In the first minute after preparation, 10% of the virus is inactivated. The rate constant for viral inactivation is ___ × 10−3 min−1. (Nearest integer) [Use : ln 10 = 2. 303; log10 3 = 0. 477 property of logarithm : log xy = y log x]

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.Potassium chlorate is prepared by electrolysis of KCl in basic solution as shown by following equation. 6 OH−+ Cl−→ClO−3 + 3H2O + 6e− A current of xA has to be passed for 10 h to produce 10. 0 g of potassium chlorate. the value of x is __________. (Nearest integer) (Molar mass of KClO3 = 122. 6 g mol−1 F = 96500 C )

Q57.Number of amphoteric compounds among the following is (A) BeO JEE Main 2021 (24 Feb Shift 1) JEE Main Previous Year Paper (B) BaO (C) BeOH2 (D) Sr OH2

Q57.A KCl solution of conductivity 0. 14 S m−1 shows a resistance of 4. 19Ω in a conductivity cell. If the same cell is filled with an HCl solution, the resistance drops to 1. 03Ω . The conductivity of the HCl solution is ____ ×10−2 S m−1 . (Round off to the Nearest Integer).

Q57. Consider the above chemical reaction. The total number of stereoisomers possible for Product "P" 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 _.

Q57.A certain element crystallises in a bcc lattice of unit cell edge length 27 A. If the same element under the same o conditions crystallises in the fcc lattice, the edge length of the unit cell in A will be __________. (Round off to the Nearest Integer). [Assume each lattice point has a single atom] [Assume √3 = 1. 73, √2 = 1. 41]

Q57.In a solvent 50% of an acid HA dimerizes and the rest dissociates. The van't Hoff factor of the acid is _____ ×10−2 (Round off to the nearest integer)

Q57.For the reaction 2 Fe3+(aq) + 2I−(aq) →2 Fe2+(aq) + I2( s) the magnitude of the standard molar free energy change, ΔrG∘m = − ______ kJ (Round off to the Nearest Integer). JEE Main 2021 (18 Mar Shift 1) JEE Main Previous Year Paper Q58. 2 NO(g) + Cl2( g) ⇌2 NOCl(s) This reaction was studied at −10°C and the following data was obtained run [NO]0 [Cl2]0 r0 1 0.10 0.10 0.18 2 0.10 0.20 0.35 3 0.20 0.20 1.40 [NO]0 and [Cl2]0 are the initial concentrations and r0 is the initial reaction rate. The overall order of the reaction is (Round off to the Nearest Integer).

Q57.These are physical properties of an element (A) Sublimation enthalpy (B) Ionisation enthalpy (C) Hydration enthalpy (D) Electron gain enthalpy The total number of above properties that affect the reduction potential is (Integer answer)

Q57.The magnitude of the change in oxidising power of the MnO−4 / Mn2+ couple is x × 10−4 V if the H+ concentration is decreased from 1 M to 10−4M at 25°C. (Assume concentration of MnO−4 and Mn2+ to be same on change in H+ concentration). The value of x is __________. (Rounded off to the nearest integer) [Given: 2.303 RT = 0. 059] F

Q57.Consider the following reaction MnO−4 + 8H+ + 5e−→Mn+2 + 4H2O , E°= 1. 51 V The quantity of electricity required in Faraday to reduce five moles of MnO−4 is

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)

Q58.Consider the sulphides HgS, PbS, CuS, Sb2 S3, As2 S3 and CdS. Number of these sulphides soluble in 50% HNO3 is ___________ .

Q58.The oxygen dissolved in water exerts a partial pressure of 20 kPa in the vapour above water. The molar solubility of oxygen in water is ______ ×10−5 mol dm−3. (Round off to the Nearest Integer). [Given : Henry's law constant = KH = 8. 0 × 104 kPa for O2. Density of water with dissolved oxygen = 1. 0 kg dm−3 ]

Q58. PCl5(g) →PCl3(g) + Cl2(g) In the above first order reaction the concentration of PCl5 reduces from initial concentration 50 mol L−1 to 10 mol L−1 in 120 minutes at 300 K. The rate constant for the reaction at 300 K is x × 10−2 min−1. The value of x is __________. [Given log 5 = 0. 6989 ]

Q58.For the reaction A →B, the rate constant k (in s-1) is given by 2 . 47 × 103 log10k = 20 . 35 - T The energy of activation in kJ mol-1 is ________ . (Nearest integer) [Given : R = 8 . 314 J K-1 mol-1]

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

Q58.The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to h2 . The value of x ma20 10 x is ( a0 is radius of Bohr's orbit) (Nearest integer) [Given: π = 3. 14]

Q58.CO2 gas is bubbled through water during a soft drink manufacturing process at 298 K. If CO2 exerts a partial pressure of 0 . 835 bar then x m mol of CO2 would dissolve in 0 . 9 L of water. The value of x is _______. (Nearest integer) (Henry's law constant for CO2 at 298 K is 1 . 67 × 103 bar)