Practice Questions

Q49.A container of fixed volume contains a gas at 27∘C. To double the pressure of the gas, the temperature of gas should be raised to ______ ∘C.

Q51.Concentrated nitric acid is labelled as 75% by mass. The volume in mL of the solution which contains 30 g of nitric acid is ____. Given : Density of nitric acid solution is 1.25 g/mL . (1) 40 (2) 32 (3) 45 (4) 55

Q54.The element that does not belong to the same period of the remaining elements (modern periodic table) is: 2025 (23 Jan Shift 1) JEE Main Previous Year Paper (1) Iridium (2) Platinum (3) Osmium (4) Palladium

Q57. Which among the following react with Hinsberg's reagent? Choose the correct answer from the options given below: (1) A, B and E Only (2) A, C and E Only (3) C and D Only (4) B and D Only

Q66.What is the freezing point depression constant of a solvent, 50 g of which contain 1 g non volatile solute (molar mass 256 g mol−1 ) and the decrease in freezing point is 0.40 K ? (1) 3.72 K kg mol−1 (2) 1.86 K kg mol−1 (3) 4.43 K kg mol−1 (4) 5.12 K kg mol−1 2025 (28 Jan Shift 1) JEE Main Previous Year Paper

Q70.The correct stability order of the following species/molecules is: (1) q > r > p (2) r > q > p (3) q > p > r (4) p > q > r Q71. 1 The standard enthalpy and standard entropy of decomposition of N2O4 to NO2 are 55.0 kJ mol−1 and 175.0 J/K/mol respectively. The standard free energy change for this reaction at 25∘C in J mol−1 is ______ (Nearest integer)

Q71.The compound with molecular formula C6H6 , which gives only one monobromo derivative and takes up four moles of hydrogen per mole for complete hydrogenation has ________ = electrons. 2025 (22 Jan Shift 2) JEE Main Previous Year Paper Q72.20 mL of 2 M NaOH solution is added to 400 mL of 0.5 M NaOH solution. The final concentration of the solution is _______ ×10−2M. (Nearest integer)

Q71.In Carius method of estimation of halogen, 0.25 g of an organic compound gave 0.15 g of silver bromide (AgBr). The percentage of Bromine in the organic compound is … … ×10−1% (Nearest integer). (Given : Molar mass of Ag is 108 and Br is 80 g mol−1 )

Q71.Electrolysis of 600 mL aqueous solution of NaCl for 5 min changes the pH of the solution to 12 . The current in Amperes used for the given electrolysis is ____. (Nearest integer).

Q71.Xg of benzoic acid on reaction with aq NaHCO3 released CO2 that occupied 11.2 L volume at STP. X is _____ g.

Q71.The number of molecules/ions that show linear geometry among the following is ________ SO2, BeCl2, CO2, N−3 , NO2, F2O, XeF2, NO+2 , I−3 , O3

Q71.The formation enthalpies, ΔHf⊖ for H(g) and O(g) are 220.0 and 250.0 kJ mol−1 , respectively, at 298.15 K , and ΔHf ⊖ for H2O(g) is −242.0 kJ mol−1 at the same temperature. The average bond enthalpy of the O −H bond in water at 298.15 K is __________ kJmol−1 (nearest integer).

Q72. A → B The molecule A changes into its isomeric form B by following a first order kinetics at a temperature of 1000 K . If the energy barrier with respect to reactant energy for such isomeric transformation is 191.48 kJ mol−1 and the frequency factor is 1020 , the time required for 50% molecules of A to become B is _________ picoseconds (nearest integer). [R = 8.314 J K−1 mol−1]

Q72.The observed and normal molar masses of compound MX2 are 65.6 and 164 respectively. The percent degree of ionisation of MX2 is … … %. (Nearest integer)

Q72.Consider the following reaction occurring in the blast furnace: Fe3O4( s) + 4CO(g) →3Fe(l) + 4CO2( g) ' x ' kg of iron is produced when 2.32 × 103 kgFe3O4 and 2.8 × 102 kgCO are brought together in the furnace. The value of ' x ' is _____. (nearest integer) Given: molar mass of Fe3O4 = 232 g mol−1 molar mass of CO = 28 g mol−1 molar mass of Fe = 56 g mol−1} Q73. 37.8 g N2O5 was taken in a 1 L reaction vessel and allowed to undergo the following reaction at 500 K 2 N2O5( g) ⇌2 N2O4( g) + O2( g) The total pressure at equilibrium was found to be 18.65 bar. Then, Kp = ______ ×10−2 [nearest integer] Assume N2O5 to behave ideally under these conditions. Given: R = 0.082 bar Lmol−1 K−1

Q72.Given below are some nitrogen containing compounds ∣∣∣ 2025 (29 Jan Shift 1) JEE Main Previous Year Paper Each of them is treated with HCl separately. 1.0 g of the most basic compound will consume _______ mg of HCl. (Given molar mass in gmol−1C : 12, H : 1, O : 16, Cl : 35.5)

Q72.A group 15 element forms dπ −dπ bond with transition metals. It also forms hydride, which is a strongest base among the hydrides of other group members that form dπ −dπ bond. The atomic number of the element is ____.

Q72.Isomeric hydrocarbons → negative Baeyer's test (Molecular formula C9H12 ) The total number of isomers from above with four different non-aliphatic substitution sites is -

Q72.For the thermal decomposition of N2O5( g) at constant volume, the following table can be formed, for the reaction mentioned below. 2 N2O5( g) →2 N2O4( g) + O2( g) x = … × 10−3 atm [nearest integer] Given : Rate constant for the reaction is 4.606 × 10−2 s−1 .

Q72.The molarity of a 70% (mass / mass) aqueous solution of a monobasic acid (X) is __________ ×10−1 M(Nearest integer) [Given: Density of aqueous solution of (X) is 1.25 g mL−1 Molar mass of the acid is 70 g mol−1 ] 2025 (28 Jan Shift 1) JEE Main Previous Year Paper

Q72.A compound ' X′ absorbs 2 moles of hydrogen and ' X′ upon oxidation with KMnO4 ∣H+ gives The total number of σ bonds present in the compound ' X′ is______

Q73.Consider the following sequence of reactions: 11.25 mg of chlorobenzene will produce __________ ×10−1mg of product B . (Consider the reactions result in complete conversion.) [Given molar mass of C, H, O, N and Cl as 12, 1, 16, 14 and 35.5 g mol−1 respectively]

Q73.Consider the following low-spin complexes K3 [Co(NO2)6], K4 [Fe(CN)6], K3 [Fe(CN)6], Cuu2 [Fe(CN)6] and Zn2 [Fe(CN)6] The sum of the spin-only magnetic moment values of complexes having yellow colour is. _____ B.M. (answer in nearest integer)

Q73. Consider the following sequence of reactions : Molar mass of the product formed (A) is _______ gmol−1 .

Q73.Consider the following cases of standard enthalpy of reaction (ΔH∘r in kJmol−1) 7 C2H6( g) + O2( g) →2CO2( g) + 3H2O(l)ΔH∘1 = −1550 2 C (graphite) + O2( g) →CO2( g) ΔH∘2 = −393.5 The magnitude of ΔH∘fC2H6( g) is _______ 1 H2( g) + O2( g) →H2O(l) ΔH∘3 = −286 2 kJmol−1 (Nearest integer).