Practice Questions

Q60.The standard reduction potential values of some of the p-block ions are given below. Predict the one with the strongest oxidising capacity. (1) E⊖ = +1.67 V (2) E⊖ = +1.15 V Pb4+/Pb2+ Sn4+/Sn2+ (3) E⊖ = −1.66 V (4) E⊖T1/Tl/2.26 V Al3+/Al

Q61.Which of the following is/are not correct with respect to energy of atomic orbitals of hydrogen atom? (A) 1 s < 2p < 3 d < 4 s (B) 1 s < 2 s = 2p < 3 s = 3p (C) 1 s < 2 s < 2p < 3 s < 3p (D) 1 s < 2 s < 4 s < 3 d 2025 (28 Jan Shift 2) JEE Main Previous Year Paper Choose the correct answer from the options given below : (1) (A) and (C) only (2) (B) and (D) only (3) (C) and (D) only (4) (A) and (B) only

Q61. Ksp for Cr(OH)3 is 1.6 × 10−30 . What is the molar solubility of this salt in water? (1) 1.8×10−30 (2) 5√1.8 × 10−30 27 × 10−30 (3) 4√1.6×10−3027 (4) 2√1.6

Q62.In the given structure, number of sp and sp2 hybridized carbon atoms present respectively are : (1) 4 and 5 (2) 3 and 5 (3) 3 and 6 (4) 4 and 6 2025 (24 Jan Shift 2) JEE Main Previous Year Paper

Q62.Which of the following statement is not true for radioactive decay? (1) Decay constant increases with increase in (2) Amount of radioactive substance remained after temperature. three half lives is 1 th of original amount. 8 (3) Decay constant does not depend upon (4) Half life is ln 2 times of rate constant1 . temperature.

Q62.The type of oxide formed by the element among Li, Na, Be, Mg, B and Al that has the least atomic radius is : (1) A2O (2) A2O3 (3) AO2 (4) AO

Q63.Given below are two statements : Statement (I) : The boiling points of alcohols and phenols increase with increase in the number of C-atoms. Statement (II) : The boiling points of alcohols and phenols are higher in comparison to other class of compounds such as ethers, haloalkanes. In the light of the above statements, choose the correct answer from the options given below : (1) Both Statement I and Statement II are false (2) Both Statement I and Statement II are true (3) Statement I is false but Statement II is true (4) Statement I is true but Statement II is false

Q63.Given below are two statements I and II. Statement I: Dumas method is used for estimation of "Nitrogen" in an organic compound. Statement II: Dumas method involves the formation of ammonium sulphate by heating the organic compound with conc H2SO4 . In the light of the above statements, choose the correct answer from the options given below (1) Statement I is true but Statement II is false (2) Both Statement I and Statement II are false (3) Statement I is false but Statement II is true (4) Both Statement I and Statement II are true

Q63.Total number of sigma ( σ ) and pi(π) bonds respectively present in hex-1-en-4-yne are : (1) 3 and 13 (2) 11 and 3 (3) 13 and 3 (4) 14 and 3

Q65.Given below are two statements : Statement (I): According to the Law of Octaves, the elements were arranged in the increasing order of their atomic number. Statement (II): Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers. In the light of the above statements, choose the correct answer from the options given below : (1) Both Statement (I) and Statement (II) are false. (2) Both Statement (I) and Statement (II) are true. (3) Statement (I) is false but Statement (II) is true. (4) Statement (I) is true but Statement (II) is false. 2025 (28 Jan Shift 2) JEE Main Previous Year Paper

Q66.Match List - I with List - II. List −I List −II (A) Bronze (I) Cu, Ni (B) Brass (II) Fe, Cr, Ni, C (C) UKsilvercoin (III) Cu, Zn (D) Stainlesssteel (IV ) Cu, Sn Choose the correct answer from the options given below : (1) (A)-(IV), (B)-(II), (C)-(III), (D)-(I) (2) (A)-(IV), (B)-(III), (C)-(I), (D)-(II) (3) (A)-(III), (B)-(IV), (C)-(II), (D)-(I) (4) (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

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

Q67.The correct option with order of melting points of the pairs (Mn, Fe), (Tc, Ru) and (Re, Os) is : (1) Fe < Mn, Ru < Tc and Re < Os (2) Mn < Fe, Tc < Ru and Os < Re (3) Mn < Fe, Tc < Ru and Re < Os (4) Fe < Mn, Ru < Tc and Os < Re 2025 (29 Jan Shift 1) JEE Main Previous Year Paper

Q67.Match the LIST-I with LIST-II Choose the correct answer from the options given below: (1) A-II, B-I, C-III, D-IV (2) A-II, B-III, C-I, D-IV (3) A-IV, B-I, C-III, D-II (4) A-IV, B-III, C-I, D-II

Q68.pH of water is 7 at 25∘C. If water is heated to 80∘C., it's pH will : (1) Decrease (2) H+ concentration increases, OH− concentration decreases (3) Remains the same (4) Increase 2025 (23 Jan Shift 2) 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)

Q70.If C (diamond ) →C (graphite ) + XkJmol−1 C( diamond ) + O2( g) →CO2( g) + YkJmol−1 C (graphite) +O2( g) →CO2( g) + ZkJmol−1 at constant temperature. Then (1) X=-Y+Z (2) -X=Y+Z (3) X=Y+Z (4) X=Y-Z

Q71.In the sulphur estimation, 0.20 g of a pure organic compound gave 0.40 g of barium sulphate. The percentage of sulphur in the compound is ______ ×10−1% . (Molar mass : O = 16, S = 32, Ba = 137 in gmol−1 ) 2025 (29 Jan Shift 2) JEE Main Previous Year Paper

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).

Q74.Quantitative analysis of an organic compound (X) shows following \% composition. C : 14.5% Cl : 64.46\% H: 1.8 \% (Empirical formula mass of the compound (X) is __________ ×10−1 (Given molar mass in gmol−1 of C : 12, H : 1, O : 16, Cl : 35.5 )

Q75.The complex of Ni2+ ion and dimethyl glyoxime contains ________ number of Hydrogen (H) atoms. 2025 (22 Jan Shift 2) JEE Main Previous Year Paper

Q75.Total number of non bonded electrons present in NO2− ion based on Lewis theory is 2025 (29 Jan Shift 2) JEE Main Previous Year Paper

Q31.Combustion of glucose (C6H12O6) produces CO2 and water. The amount of oxygen (in g) required for the complete combustion of 900 g of glucose is : [Molar mass of glucose in gmol−1 = 180 ] (1) 480 (2) 800 (3) 960 (4) 32

Q31.Compare the energies of following sets of quantum numbers for multielectron system. (A) n = 4, 1 = 1 (B) n = 4, l = 2 (C) n = 3, 1 = 1 (D) n = 3, 1 = 2 (E) n = 4, 1 = 0 Choose the correct answer from the options given below : (1) (B) > (A) > (C) > (E) > (D) (2) (E) < ( C ) < (D) < ( A ) < ( B ) (3) (E) > ( C ) > ( A ) > ( D ) > (B) (4) (C) < (E) < (D) < (A) < (B)

Q31.Given below are two statements: Statement - I: Along the period, the chemical reactivity of the element gradually increases from group 1 to group 18 . Statement - II: The nature of oxides formed by group 1 element is basic while that of group 17 elements is acidic. In the the light above statements, choose the most appropriate from the questions given below: (1) Both statement I and Statement II are true. (2) Statement I is true but Statement II is False. (3) Statement I is false but Statement II is true. (4) Both Statement I and Statement II is false.