Practice Questions

Q53.For combustion of one mole of magnesium in an open container at 300 K and 1 bar pressure, ΔCH⊖= −601. 70 kJ mol−1 , the magnitude of change in internal energy for the reaction is kJ. (Nearest integer) (Given : R = 8. 3 J K−1 mol−1 ) Q54. 0. 01 MKMnO4 solution was added to 20. 0 mL of 0. 05M Mohr 's salt solution through a burette. The initial reading of 50 mL burette is zero. The volume of KMnO4 solution left in the burette after the end point is....... mL. (nearest integer) JEE Main 2022 (28 Jun Shift 2) JEE Main Previous Year Paper

Q53.The molar heat capacity for an ideal gas at constant pressure is 20. 785 J K−1 mol−1 . The change in internal energy is 5000 J upon heating it from 300 K to 500 K. The number of moles of the gas at constant volume JEE Main 2022 (27 Jul Shift 1) JEE Main Previous Year Paper is____ (Given: R = 8. 314 J K−1 mol−1 )

Q53.For the reaction given below: CoCl3. xNH3 + AgNO3(aq) → If two equivalents of AgCl precipitate out, then the value of x will be _______

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

Q53.The number of paramagnetic species among the following is B2, Li2, C2, C2- , O22 - , O2+ and He2+

Q53.For the reaction H2F2g →H2g + F2g JEE Main 2022 (26 Jul Shift 2) JEE Main Previous Year Paper ΔU = - 59 . 6 kJ mol-1 at 27 °C The enthalpy change for the above reaction is - ____ kJmol-1 (nearest integer) (Given : R = 8 . 314JK-1 mol-1) . Q54.20 mL of 0 . 02 M hypo solution is used for the titration of 10 mL of copper sulphate solution, in the presence of excess of KI using starch as an indicator. The molarity of Cu2 + is found to be _____ × 10-2M (nearest integer) Given : 2Cu2 + + 4I- →Cu2I2 + I2I2 + 2S2O3-2 → 2I— + S4O6-2

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]

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.The enthalpy of combustion of propane, graphite and dihydrogen at 298 K are: -2220 . 0 kJ mol-1, -393 . 5 kJ mol-1 and -285 . 8 kJ mol-1 respectively. The magnitude enthalpy of formation of propane C3H8 is _____ kJmol-1. (Nearest integer)

Q53.Total number of possible stereoisomers of dimethyl cyclopentane is

Q53.Number of electrophillic centres in the given compound is___

Q53.The wavelength of an electron and a neutron will become equal when the velocity of the electron is x times the velocity of neutron. The value of x is____(the nearest integer)(Mass of electron is 9. 1 × 10−31 kg and mass of neutron is 1. 6 × 10−27 kg)

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

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.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.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.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 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)

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.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.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.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.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)