Practice Questions

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

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

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

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 )

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.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.Manganese (VI) has ability to disproportionate in acidic solution. The difference in oxidation states of two ions it forms in acidic solution is Q54. 0. 2 g of an organic compound was subjected to estimation of nitrogen by Dumas method in which volume of N2 evolved (at STP) was found to be 22. 400 mL. The percentage of nitrogen in the compound is - [nearest integer] (Given: Molar mass of N2 is 28 g mol−1 , Molar volume of N2 at STP : 22. 4 L)

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.Total number of possible stereoisomers of dimethyl cyclopentane is

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 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.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.Number of electrophillic centres in the given compound is___