Practice Questions

Q53.When 5 moles of He gas expand isothermally and reversibly at 300 K from 10 litre to 20 litre, the magnitude of the maximum work obtained is J. [nearest integer ] (Given : R = 8. 3 J K−1 mol−1 and log 2 = 0. 3010)

Q53.Among the following the number of state variable is Internal energy (U) Volume (V) Heat (q) Enthalpy (H)

Q53.Amongst SF4, XeF4, CF4 and H2O, the number of species with two lone pairs of electrons is

Q53.The sum of number of lone pairs of electrons present on the central atoms of XeO3, XeOF4 and XeF6 is

Q53.Number of grams of bromine that will completely react with 5 . 0 g of pent-1-ene is____ × 10-2 g. (Atomic mass of Br = 80 g / mol) [Nearest integer]

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.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.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.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.Ka for butyric acid C3H7COOH is 2 × 10-5. ThepH of 0 . 2M solution of butyric acid is____ × 10-1. (Nearest integer) [Given log2 = 0 . 30]

Q54.At 310 K, the solubility of CaF2 in water is 2. 34 × 10−3 g/100 mL . The solubility product of CaF2 is ---- ×10−8(mol /L)3 (nearest integer). (Given molar mass : CaF2 = 78 g mol−1 ) Q55. 20 mL of 0. 02 MK2 Cr2 O7 solution is used for the titration of 10 mL of Fe2+ solution in the acidic medium. The molarity of Fe2+ solution is____ ×10−2M

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.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.Observe structures of the following compounds The total number of structures/compounds which possess asymmetric carbon atoms is Q55. 1. 2 mL of acetic acid is dissolved in water to make 2. 0 L of solution. The depression in freezing point observed for this strength of acid is 0. 0198 °C . The percentage of dissociation of the acid is (Nearest integer) [Given : Density of acetic acid is 1. 02 g mL−1 Molar mass of acetic acid is 60 g mol−1 Kf(H2O) = 1. 85 K kg mol−1 ]

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

Q54.In bromination of Propyne, with Bromine 1, 1, 2, 2-tetrabromopropane is obtained in 27% yield. The amount of 1, 1, 2, 2 tetrabromopropane obtained from 1 g of Bromine in this reaction is_____ ×10−1 g . (Molar Mass : Bromine = 80 g/ mol)

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.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.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 .

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.Two elements A and B which form 0. 15 moles of A2B and AB3 type compounds. If both A2B and AB3 weigh equally, then the atomic weight of A is____times of atomic weight of B. Q56. 2 g of a non-volatile non-electrolyte solute is disolved in 200 g of two different solvents A and B whose ebullioscopic constants are in the ratio of 1 : 8. The elevation in boiling points of A and B are in the ratio x (x : y). The value of y is____(Nearest Integer) y

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. BeO reacts with HF in presence of ammonia to give [A] which on thermal decomposition produces [B] and ammonium fluoride. Oxidation state of Be in [A] is Q56. 0. 25 g of an organic compound containing chlorine gave 0. 40 g of silver chloride in Carius estimation. The percentage of chlorine present in the compound is [in nearest integer] (Given: Molar mass of Ag is 108 g mol−1 and that of Cl is 35. 5 g mol−1 )