Practice Questions

Q56.In a solid AB, A atoms are in ccp arrangement and B atoms occupy all the octahedral sites. If two atoms from the opposite faces are removed, then the resultant stoichiometry of the compound is AxBy . The value of x is [nearest integer]

Q56.At 298 K, the equilibrium constant is 2 × 1015 for the reaction: Cu(s) + 2 Ag+(aq) ⇌Cu2+(aq) + 2 Ag(s) The equilibrium constant for the reaction 2 1 Cu2+(aq) + Ag(s) ⇌12 Cu(s) + Ag+(aq) is x × 10−8 . The value of x is ______. (Round off the answer to the nearest integer) JEE Main 2022 (26 Jul Shift 1) JEE Main Previous Year Paper

Q56.A sample of 0. 125 g of an organic compound when analysed by Duma's method yields 22. 78 mL of nitrogen gas collected over KOH solution at 280 K and 759 mmHg . The percentage of nitrogen in the given organic compound is____ (a) The vapour pressure of water at 280 K is 14. 2 mmHg (b) R = 0. 082 L atm K−1 mol−1 JEE Main 2022 (28 Jul Shift 2) JEE Main Previous Year Paper

Q56.A radioactive element has a half life of 200 days. The percentage of original activity remaining after 83 days is____(Nearest integer) (Given : antilog 0. 125 = 1. 333, antilog 0. 693 = 4. 93) Q57. [Fe (CN)6]4− [Fe (CN)6]3− [Ti (CN)6]3− [Ni (CN)4]2− [Co (CN)6]3− Among the given complexes, number of paramagnetic complexes is

Q56.The separation of two coloured substances was done by paper chromatography. The distances travelled by solvent front, substance A and substance B from the base line are 3. 25 cm. 2. 08 cm and 1. 05 cm . respectively. The ratio of Rf values of A to B is (Answer the nearest integer)

Q56.At 345 K, the half life for the decomposition of a sample of a gaseous compound initially at 55 . 5 kPa was 340 s. When the pressure was 27 . 8 kPa, the half life was found to be 170 s. The order of the reaction is - [integer answer]

Q56.Assuming 1μg of trace radioactive element X with a half life of 30 years is absorbed by a growing tree. The amount of X remaining in the tree after 100 years is_____ × 10-1μg. [Given : ln10 = 2 . 303; log2 = 0 . 30]

Q56.In the following reaction ​ The % yield for reaction I is 60% and that of reaction II is 50%. The overall yield of the complete reaction is % Q57. 2NO + 2H2 →N2 + 2H2O The above reaction has been studied at 800 °C . The related data are given in the table below Initial Reaction serial Initial pressure of Initial rate Pressure −dp /s) number H2/ kPa ( dt )/(kPa of NO / kPa 1 65. 6 40. 0 0. 135 2 65. 6 20. 1 0. 033 3 38. 6 65. 6 0. 214 4 19. 2 65. 6 0. 106 The order of the reaction with respect to NO is____

Q56.The resistance of a conductivity cell containing 0. 01 MKCl solution at 298 K is 1750 Ω. If the conductivity of 0. 01 MKCl solution at 298 K is 0. 152 × 10−3 S cm−1 , then the cell constant of the conductivity cell is____ ×10−3 cm−1

Q56.A flask is filled with equal moles of A and B. The half lives of A and B are 100 s and 50 s respectively and are independent of the initial concentration. The time required for the concentration of A to be four times that of B is____ s. (Given : ln 2 = 0. 693 ) Q57. 2. 0 g of H2 gas is adsorbed on 2. 5 g of platinum powder at 300 K and 1 bar pressure. The volume of the gas adsorbed per gram of the adsorbent is mL (Given : R = 0. 083 L bar K−1 mol−1 )

Q56.The number of non-ionisable protons present in the product B obtained from the following reaction is___ C2H5OH + PCl3 →C2H5Cl + A A + PCl3 →B

Q57.The total number of monobromo derivatives formed by the alkanes with molecular formula C5H12 is (excluding stereo isomers)

Q57.The equation k = (6. 5 × 1012 s−1)e−26000 K/T is followed for the decomposition of compound A. The activation energy for the reaction is ____ KJ mol−1 . [nearest integer] (Given: R = 8. 314 J K−1 mol−1 )

Q57.The activation energy of one of the reactions in a biochemical process is 532611 J mol−1 . When the temperature falls from 310 K to 300 K , the change in rate constant observed is k300 = x × 10−3k310° . The value of x is [Given: ln 10 = 2. 3 R = 8. 3 J K−1 mol−1 ]

Q57.Metal M crystallizes into a FCC lattice with the edge length of 4. 0 × 10−8 cm. The atomic mass of the metal is g/ mol. (Use : NA = 6. 02 × 1023 mol−1 , density of metal, M = 9. 03 g cm−3 )

Q57.The spin-only magnetic moment value of the compound with strongest oxidizing ability among MnF4, MnF3 and MnF2 is_____ B . M (nearest integer)

Q57.For the given first order reaction A →B the half life of the reaction is 0 . 3010 min. The ratio of the initial concentration of reactant to the concentration of reactant at time 2 . 0 min will be equal to _____. (Nearest integer)

Q57.The half life for the decomposition of gaseous compound A is 240 s when the gaseous pressure was 500 Torr initially. When the pressure was 250 Torr, the half life was found to be 4 . 0 min. The order of the reaction is _____ (Nearest integer)

Q57.When 200 mL of 0. 2 M acetic acid is shaken with 0. 6 g of wood charcoal, the final concentration of acetic acid after adsorption is 0. 1 M. The mass of acetic acid adsorbed per gram of carbon is g .

Q57.Resistance of a conductivity cell (cell constant 129 m−1 ) filled with 74. 5 ppm solution of KCl is 100 Ω (labelled as solution 1). When the same cell is filled with KCl solution of 149 ppm, the resistance is 50 Ω (labelled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is i.e. ∧1 = x × 10−3 . The ∧2 value of x is____Given, molar mass of KCl is 74. 5 g mol−1 )

Q57.The distance between Na+ and Cl- ions in solid NaCl of density 43 . 1 gcm-3 is . . . . . × 10-10 m. (Nearest Integer) (Given : NA = 6 . 02 × 1023 mol-1)

Q57.The cell potential for the following cell Pt|H2(g)|H+(aq) Cu2+(0 .01 M) Cu(s) is 0. 576 V at 298 K . The pH of the solution is (Nearest integer) (Given : Eo = 0. 34 V and 2.303F RT = 0. 06 V ) Cu2+ / Cu

Q57.The limiting molar conductivities of NaI, NaNO3 and AgNO3 are 12. 7, 12. 0 and 13. 3 mSm2 mol−1 , respectively (all at 25 °C ). The limiting molar conductivity of AgI at this temperature is____ mSm2 mol−1 .

Q57.The solubility product of a sparingly soluble salt A2X3 is 1. 1 × 10−23 . If specific conductance of the solution is 3 × 10−5 Sm−1 , the limiting molar conductivity of the solution is x × 10−3 S m2 mol−1 . The value of x is

Q57.Consider the following sulphure based oxoacids. H2SO3, H2SO4, H2S2O8 and H2S2O7. Amongst these oxoacids, the number of those with peroxo O - Obond is