Practice Questions

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.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

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

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

Q53.for a real gas at 25 °C temperature and high pressure ( 99 bar) the value of compressibility factor is 2 , so the value of Van 1der Waal's constant ' b' should be_____ ×10−2 L mol−1 (Given R = 0. 083 L bar K−1 mol−1 )

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

Q53.If the solubility product of PbS is 8 × 10−28 , then the solubility of PbS in pure water at 298 K is x × 10−16 mol L−1 . The value of x is____ (Nearest integer) [Given √2 = 1. 41]

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.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.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 electrophillic centres in the given compound 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]

Q53.A rigid nitrogen tank stored inside a laboratory has a pressure of 30 atm at 06: 00 am when the temperature is 27 °C. At 03: 00pm, when the temperature is 45 °C, the pressure in the tank will be _____ atm. [nearest integer]

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.Total number of possible stereoisomers of dimethyl cyclopentane is

Q53.Kjeldahl's method was used for the estimation of nitrogen in an organic compound. The ammonia evolved from 0. 55 g of the compound neutralised 12. 5 mL of 1M H2 SO4 solution. The percentage of nitrogen in the compound is (Nearest integer)

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

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

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.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.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.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 .