Practice Questions

Q51.Chlorophyll extracted from the crushed green leaves was dissolved in water to make 2 L solution of Mg of concentration 48ppm. The number of atoms of Mg in this solution is x × 1020 atoms. The value of x is (Nearest Integer) (Given : Atomic mass of Mg is 24 g mol−1 , NA = 6. 02 × 1023 mol−1 )

Q51. CNG is an important transportation fuel. When 100 gCNG is mixed with 208 g oxygen in vehicles, it leads to the formation of CO2 and H2O and produces large quantity of heat during this combustion, then the amount of carbon dioxide, produced in grams is [nearest integer] [Assume CNG to be methane]

Q51.A 1 . 84mg sample of polyhydric alcoholic compound 'X' of molar mass 92 . 0 g / mol gave 1 . 344 mL of H2 gas at STP. The number of alcoholic hydrogen present in compound 'X' is

Q51.In the given reaction, X + Y + 3Z ⇄XYZ3 if one mole of each of X and Y with 0 . 05 mol of Z gives compound XYZ3. (Given : Atomic masses of X, Y and Z are 10,20 and 30amu, respectively). The yield of XYZ3 is____g.

Q51.At 300 K, a sample of 3. 0 g of gas A occupies the same volume as 0. 2 g of hydrogen at 200 K at the same pressure. The molar mass of gas A is g mol−1 . (nearest integer) Assume that the behaviour of gases as ideal. (Given: The molar mass of hydrogen (H2) gas is 2. 0 g mol−1 .)

Q51.The complete combustion of 0. 492 g of an organic compound containing ' C', ' H' and ' O' gives 0. 793 g of CO2 and 0. 442 g of H2O. The percentage of oxygen composition in the organic compound is____.(nearest integer) Q52. 100 g of an ideal gas is kept in a cylinder of 416 L volume at 27 °C under 1. 5 bar pressure. The molar mass of the gas is g mol−1 . (Nearest integer) (Given : R = 0. 083 L bar K−1 mol−1 )

Q51.A protein 'A' contains 0 . 30% of glycine (molecular weight 75). The minimum molar mass of the protein 'A' is____ × 103 g mol-1 [nearest integer] JEE Main 2022 (25 Jun Shift 2) JEE Main Previous Year Paper

Q51.The minimum uncertainty in the speed of an electron in one dimensional region of length 2ao (Where ao = Bohr radius 52. 9 pm) is____ kms−1 (Nearest integer) (Given : Mass of electron = 9. 1 × 10−31 kg , Planck's constant h = 6. 63 × 10−34 Js)

Q51.Geraniol, a volatile organic compound, is a component of rose oil. The density of the vapour is 0. 46 gL−1 at 257 °C and 100 mmHg . The molar mass of geraniol is (Nearest Integer) [Given R = 0. 082 L atm K−1 mol−1 ] Q52. 17. 0 g of NH3 completely vapourises at −33. 42 °C and 1 bar pressure and the enthalpy change in the process is 23. 4 kJ mol−1 . The enthalpy change for the vapourisation of 85 g of NH3 under the same conditions is kJ.

Q51.Among the following species N2, N2+, N2- , N22 - , O2, O2+, O2- , O22 - the number of species showing diamagnetism is

Q51.If the work function of a metal is 6. 63 × 10−19 J, the maximum wavelength of the photon required to remove a photoelectron from the metal is____ nm. Nearest integer) [Given : h = 6. 63 × 10−34 J s, and c = 3 × 108 m s−1 ]

Q52.If the wavelength for an electron emitted from H− atom is 3. 3 × 10−10 m, then energy absorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is____times. [Given : h = 6. 626 × 10−34 Js, Mass of electron = 9. 1 × 10−31 ]

Q52.A 10 g mixture of hydrogen and helium is contained in a vessel of capacity 0 . 0125 m3 at 6 bar and 27 °C. The mass of helium in the mixture is ..... g. (Given : R = 8 . 3JK-1 mol-1 (Atomic masses of H and He are 1u and 4u, respectively)

Q52.According to MO theory, number of species/ions from the following having identical bond order is____ CN−, NO+, O2, O+2 , O2+2

Q52.A 0. 166 g sample of an organic compound was digested with conc. H2 SO4 and then distilled with NaOH. The ammonia gas evolved was passed through 50. 0 mL of 0. 5 N H2 SO4 . The used acid required 30. 0 mL of 0. 25 N NaOH for complete neutralization. The mass percentage of nitrogen in the organic compound is

Q52.For complete combustion of methanol CH3 OH(l) + 32 O2(g) →CO2(g) + 2H2O(l) the amount of heat produced as measured by bomb calorimeter is 726 kJ mol−1 at 27 °C . The enthalpy of combustion for the reaction is −x kJ mol−1 , where x is JEE Main 2022 (26 Jun Shift 1) JEE Main Previous Year Paper integer) (Given : R = 8. 3 JK−1 mol−1 ) Q53. 50 mL of 0. 1 M CH3 COOH is being titrated against 0. 1 M NaOH . When 25 mL of NaOH has been added, the pH of the solution will be____ ×10−2 . (Nearest integer) (Given : pKa(CH3 COOH) = 4. 76) log 2 = 0. 30 log 3 = 0. 48 log 5 = 0. 69 log 7 = 0. 84 log 11 = 1. 04

Q52.Consider, PF5, BrF5, PCl3, SF6, ICl4 -, ClF3 and IF5 Amongst the above molecule(s) ion(s), the number of molecule(s)/ion(s) having sp3d2 hybridisation is Q53.'x' g of molecular oxygen O2 is mixed with 200 g of neon Ne. The total pressure of the nonreactive mixture of O2 and Ne in the cylinder is 25 bar. The partial pressure of Ne is 20 bar at the same temperature and volume. The value of 'x' is [Given: Molar mass of O2 = 32 g mol-1. Molar mass of Ne = 20 g mol-1] JEE Main 2022 (29 Jul Shift 2) JEE Main Previous Year Paper Q54.1 . 80 g of solute A was dissolved in 62 . 5 cm3 of ethanol and freezing point of the solution was found to be 155 . 1 K. The molar mass of solute A is gmol-1. [Given: Freezing point of ethanol is 156 . 0 K. Density of ethanol is 0 . 80 g cm-3. Freezing point depression constant of ethanol is 2 . 00 K kg mol-1]

Q52.On complete combustion of 0 . 492 g of an organic compound containing C, H and O, 0 . 7938 g of CO2 and 0 . 4428 g of H2O was produced. The % composition of oxygen in the compound is____. (Nearest Integer)

Q52.When 800 mL of 0. 5M nitric acid is heated in a beaker, its volume is reduced to half and 11. 5 g of nitric acid is evaporated. The molarity of the remaining nitric acid solution is x × 10−2M. (Molar mass of nitric acid is 63 g mol−1 )

Q52.The pressure of a moist gas at 27°C is 4 atm. The volume of the container is doubled at the same temperature. The new pressure of the moist gas is … × 10-1 atm. (Nearest integer) (Given: The vapour pressure of water at 27°C is 0 . 4 atm)

Q52.When 600 mL of 0. 2M HNO3 is mixed with 400 mL of 0. 1M NaOH solution in a flask, the rise in temperature of the flask is_____ ×10−2 °C (Enthalpy of neutralisation = 57 kJ mol−1 and Specific heat of water = 4. 2 JK−1 g−1 ) (Neglect heat capacity of flask)

Q52.The number of molecule(s) or ion(s) from the following having non-planar structure is______. NO−3 , H2O2, BF3, PCl3, XeF4 , SF4, XeO3, PH+4 , SO3, [Al (OH)4]−

Q52.How many of the following molecules are with non-zero net dipole moment, NH3 , HCl, H2O , BeF2, BH3, CCl4

Q53.Number of electrophillic centres in the given compound is___

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