Practice Questions

Q54.The longest wavelength of light that can be used for the ionisation of lithium ion $\mathrm{(Li^{2+})}$ is x × 10-8 m. The value of x is (Nearest Integer) (Given : Energy of the electron in the first shell of the hydrogen atom is -2 . 2 × 10-18 J; h = 6 . 63 × 10-34Js and c = 3 × 108 ms-1)

Q54.Metal deficiency defect is shown by Fe0.93 O. In the crystal, some Fe2+ cations are missing and loss of positive charge is compensated by the presence of Fe3+ ions. The percentage of Fe2+ ions in the Fe0.93 O crystals is____(Nearest integer)

Q54.At 600 K, 2 mol of NO are mixed with 1 mol of O2 . 2 NO(g) + O2(g) ⇄2 NO2(g) The reaction occurring as above comes to equilibrium under a total pressure of 1 atm. Analysis of the system shows that 0. 6 mol of oxygen are present at equilibrium. The equilibrium constant for the reaction is____.

Q54. pH value of 0. 001 MNaOH solution is

Q54.A 2. 0 g sample containing MnO2 is treated with HCl liberating Cl2 . The Cl2 gas is passed into a solution of KI and 60. 0 mL of 0. 1 MNaS2 O3 is required to titrate the liberated iodine. The percentage of MnO2 in the sample is____. Nearest integer) [Atomic masses (in u) Mn = 55; Cl = 35. 5 : O = 16, I = 127, Na = 23, K = 39, S = 32 ]

Q54.The major product ' A' of the following given reaction has sp2 hybridized carbon atoms. JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper H+ 2, 7 -Dimethyl- 2, 6 -octadiene → A Major Product

Q54.A sealed flask with a capacity of 2 dm3 contains 11 g of propane gas. The flask is so weak that it will burst if the pressure becomes 2 MPa. The minimum temperature at which the flask will burst is ∘C. [Nearest integer] (Given: R = 8. 3 J K−1 mol−1 . Atomic masses of C and H are 12u and 1u respectively.) (Assume that propane behaves as an ideal gas.)

Q54.A mixture of hydrogen and oxygen contains 40% hydrogen by mass when the pressure is 2. 2 bar. The partial pressure of hydrogen is bar. Q55. 2. 4 g coal is burnt in a bomb calorimeter in excess of oxygen at 298 K and 1 atm pressure. The temperature of the calorimeter rises from 298 K to 300 K. The enthalpy change during the combustion of coal is −x kJ mol−1 . The value of x is_____(Given : Heat capacity of bomb calorimeter 20. 0 kJK−1 . Assume coal to be pure carbon)

Q54.While estimating the nitrogen present in an organic compound by Kjeldahl's method, the ammonia evolved from 0 . 25 g of the compound neutralized 2 . 5 mL of 2MH2SO4. The percentage of nitrogen present in organic compound is _____ .

Q54.The neutralization occurs when 10 mL of 0 . 1 M acid 'A' is allowed to react with 30 mL of 0 . 05 M base MOH2. The basicity of the acid 'A' is [M is a metal]

Q54.Compound ' P' on nitration with dil. HNO3 yields two isomers (A) and (B). These isomers can be separated by steam distillations. Isomers (A) and (B) show the intramolecular and intermolecular hydrogen bonding respectively. Compound (P) on reaction with conc. HNO3 yields a yellow compound ' C', a strong acid. The number of oxygen atoms is present in compound ' C'

Q54.The number of chiral alcohol(s) with molecular formula C4H10O is ________ (Assume stereoisomers as different chiral alcohols)

Q54.A gas ( Molar mass = 280 g mol−1 ) was burnt in excess O2 in a constant volume calorimeter and during combustion the temperature of calorimeter increased from 298. 0 K to 298. 45 K . If the heat capacity of calorimeter is 2. 5 kJ K−1 and enthalpy of combustion of gas is 9 kJ mol−1 then amount of gas burnt is____ g .

Q54. A fish swimming in water body when taken out from the water body is covered with a film of water of weight 36 g . When it is subjected to cooking at 100 °C, then the internal energy for vaporization in kJmol−1 is integer] [Assume steam to be an ideal gas. Given ΔvapH⊖ for water at 373 K and 1 bar is 41. 1 kJ mol−1 : R = 8. 31 J K−1 mol−1 ] Q55. 40% of HI undergoes decomposition to H2 and I2 at 300 K. ΔGΘ for this decompostion reaction at one atmopsphere pressure is____ Jmol−1 -[nearest integer] (Use R = 8. 31 JK−1 mol−1; log 2 = 0. 3010, ln 10 = 2. 3, log 3 = 0. 477)

Q55.For the given reactions Sn2+ + 2e−→Sn ° ° Sn4+ + 4e−→Sn the electrode potentials are ; E Sn2+ / Sn = −0. 140 V and E Sn4+ / Sn = 0. 010 V. The ° magnitude of standard electrode potential for Sn4+ / Sn2+ i.e. E Sn4+ / Sn2+ is____ ×10−2 V(Nearest integer)

Q55.The elevation in boiling point for 1 molal solution of non-volatile solute A is 3 K. The depression in freezing point for 2 molal solution of A in the same solvent is 6 K. The ratio of Kb and Kf i.e., Kb / Kf is 1: X. The value of X is

Q55.Elevation in boiling point for 1. 5 molal solution of glucose in water is 4 K. The depression in freezing point for 4. 5 molal solution of glucose in water is 4 K. The ratio of molal elevation constant to molal depression constant (Kb/Kf) is

Q55.Ionic radii of cation A+ and anion B− are 102 and 181 pm respectively. These ions are allowed to crystallize into an ionic solid. This crystal has cubic close packing for B−. A+ is present in all octahedral voids. The edge length of the unit cell of the crystal AB is___ pm .

Q55.The standard entropy change for the reaction 4Fes + 3O2g →2Fe2O3s is -550 J K-1 at 298 K [Given : The standard enthalpy change for the reaction is -165 kJ mol-1]. The temperature in K at which the reaction attains equilibrium is (Nearest Integer)

Q55.An element M crystallises in a body centred cubic unit cell with a cell edge of 300pm. The density of the element is 6 . 0 g cm-3. The number of atoms present in 180 g of the element is____ × 1023. (Nearest integer) Q56.150 g of acetic acid was contaminated with 10 . 2 g ascorbic acid C6H8O6 to lower down its freezing point by x × 10-1°C. The value of x is____ (Nearest integer). [Given Kf = 3 . 9 K kg mol-1; Molar mass of ascorbic acid = 176 g mol-1]

Q55.On reaction with stronger oxidizing agent like KIO4 , hydrogen peroxide oxidizes with the evolution of O2 . The oxidation number of I in KIO4 changes to

Q55.The normality of H2 SO4 in the solution obtained on mixing 100 mL of 0. 1M H2 SO4 with 50 mL of 0. 1M NaOH is____ ×10−1 N .

Q55.In the estimation of bromine, 0. 5 g of an organic compound gave 0. 40 g of silver bromide. The percentage of bromine in the given compound is % (nearest integer) (Relative atomic masses of Ag and Br are 108u and 80u , respectively).

Q55.Atoms of element X form hcp lattice and those of element Y occupy 32 of its tetrahedral voids. The percentage of element X in the lattice is (Nearest integer)

Q55.While performing a thermodynamics experiment, a student made the following observations, HCl + NaOH →NaCl + H2OΔH = −57. 3 kJ mol−1 CH3 COOH + NaOH →CH3 COONa + H2O ΔH = −55. 3 kJ mol−1 . JEE Main 2022 (25 Jul Shift 2) JEE Main Previous Year Paper The enthalpy of ionization of CH3 COOH as calculated by the student is kJ mol−1 .