Practice Questions

Q68.In which of the following complexes the CFSE, Δo will be equal to zero? (1) [Fe(en)3]Cl3 (2) K4 [Fe(CN)6] (3) [Fe(NH3)6]Br2 (4) K3 [Fe(SCN)6]

Q68.Identify the inorganic sulphides that are yellow in colour : (A) (NH4)2 S (B) Pbs (C) Cus (D) As2 S3 (E) As2 S5 Choose the correct answer from the options given below : (1) (A), (D) and (E) only (2) (D) and (E) only (3) (A) and (B) only (4) (A) and (C) only

Q68.Ice and water are placed in a closed container at a pressure of 1 atm and temperature 273.15 K . If pressure of the system is increased 2 times, keeping temperature constant, then identify correct observation from following (1) Volume of system increases . (2) The solid phase (ice) disappears completely. (3) Liquid phase disappears completely. (4) The amount of ice decreases.

Q68.Match the Compounds (List - I) with the appropriate Catalyst/Reagents (List - II) for their reduction into corresponding amines. Choose the correct answer from the options given below : (1) (A)-(II), (B)-(I), (C)-(III), (D)-(IV) (2) (A)-(III), (B)-(II), (C)-(IV), (D)-(I) (3) (A)-(II), (B)-(IV), (C)-(III), (D)-(I) (4) (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

Q69.Arrange the following solutions in order of their increasing boiling points. (i) 10−4M NaCl (ii) 10−4M Urea (iii) 10−3M NaCl (iv) 10−2M NaCl (1) (i) < (ii) < (iii) < (iv) (2) (iv) < (iii) < (i) < (ii) (3) (ii) < (i ) ≡(iii) < (iv) (4) (ii) < (i) < (iii) < (iv)

Q69.The d- electronic configuration of an octahedral Co(II) complex having magnetic moment of 3.95 BM is: (1) t2 g3eg0 (2) t2 g6eg1 (3) t2 g5eg2 (4) e4t23 2025 (23 Jan Shift 1) JEE Main Previous Year Paper

Q69.The incorrect decreasing order of atomic radii is (1) Si > P > Cl > F (2) Be > Mg > Al > Si (3) Al > B > N > F (4) Mg > Al > C > O

Q69.The major product of the following reaction is : (1) 2-Phenylhepta-2,5-diene (2) 6-Phenylhepta-2,4-diene (3) 6-Phenylhepta-3,5-diene (4) 2-Phenylhepta-2,4-diene

Q69.Arrange the following compounds in increasing order of their dipole moment : HBr, H2 S, NF3 and CHCl3 (1) H2 S < HBr < NF3 < CHCl3 (2) NF3 < HBr < H2 S < CHCl3 (3) HBr < H2 S < NF3 < CHCl3 (4) CHCl3 < NF3 < HBr < H2 S

Q69.Identify the coordination complexes in which the central metal ion has d4 configuration. Choose the correct answer from the options given below : (1) (B), (C) and (D) only (2) (C) and (E) only (3) (B) and (D) only (4) (A), (B) and (E) only

Q69.Which of the following mixing of 1 M base and 1 M acid leads to the largest increase in temperature? (1) 30 mLCH3COOH and 30 mL NaOH (2) 45mLCH3COOHand25mLNaOH (3) 30 mL HCl and 30 mL NaOH (4) 50 mL HCl and 20 mL NaOH 2025 (24 Jan Shift 2) JEE Main Previous Year Paper Q70. 3 S( g) + O2( g) →SO3( g) + 2xkcal 2 The heat of formation of SO2( g) is given by : 1 SO2( g) + O2( g) →SO3( g) + ykcal 2 (1) x + ykcal (2) y −2xkcal (3) 2x y kcal (4) 2x + ykcal

Q69. In the following substitution reaction: product ′P′ formed is : (1) (2) (3) (4)

Q70.Identify correct conversion during acidic hydrolysis from the following : (A) starch gives galactose. (B) cane sugar gives equal amount of glucose and fructose. (C) milk sugar gives glucose and galactose. (D) amylopectin 2025 (28 Jan Shift 2) JEE Main Previous Year Paper gives glucose and fructose. (E) amylose gives only glucose. Choose the correct answer from the options given below : (1) (A), (B) and (C) only (2) (B), (C) and (E) only (3) (C), (D) and (E) only (4) (B), (C) and (D) only

Q70.Which of the following linear combination of atomic orbitals will lead to formation of molecular orbitals in homonuclear diatomic molecules [internuclear axis in z -direction] ? A. 2pz and 2px B. 2 s and 2px C. 3 dxy 2025 (24 Jan Shift 1) JEE Main Previous Year Paper and 3 dx2−y2 D. 2 s and 2pz E. 2pz and 3dx2 −y2 Choose the correct answer from the options given below: (1) A and B Only (2) D Only (3) E Only (4) C and D Only

Q70.The correct increasing order of stability of the complexes based on Δo value is : I. [Mn(CN)6]3− II. [Co(CN)6]4− III. [Fe(CN)6]4− IV. [Fe(CN)6]3− (1) IV < III < II < I (2) I < II < IV < III (3) III < II < IV < I (4) II < III < I < IV

Q70.From the magnetic behaviour of [NiCl4]2− (paramagnetic) and [Ni(CO)4] (diamagnetic), choose the correct geometry and oxidation state. (1) [NiCl4]2−: NiII , tetrahedral [Ni(CO)4] : NiII , (2) [NiCl4]2− : NiII , square planar [Ni(CO)4] : Ni(0) square planar , square planar (3) [NiCl4]2−: NiII , tetrahedral [Ni(CO)4] : Ni(0), (4) [NiCl4]2−: Ni(0), tetrahedral [Ni(CO)4] : Ni(0), tetrahedral square planar

Q70.The maximum covalency of a non-metallic group 15 element ' E ' with weakest E −E bond is : (1) 4 (2) 6 (3) 3 (4) 5

Q70.When a non-volatile solute is added to the solvent, the vapour pressure of the solvent decreases by 10 mm of Hg . The mole fraction of the solute in the solution is 0.2 . What would be the mole fraction of the solvent if decrease in vapour pressure is 20 mm of Hg ? (1) 0.8 (2) 0.4 (3) 0.2 (4) 0.6 Q71.0.01 mole of an organic compound (X) containing 10% hydrogen, on complete combustion produced 0.9 gH2O. Molar mass of (X) is _____ gmol−1 .

Q71.The molar mass of the water insoluble product formed from the fusion of chromite ore (FeCr2O4) with Na2CO3 in presence of O2 is _______ gmol−1 .

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

Q1. Match List-I with List-II. List-I List-II A. Coefficient of viscosity I. [ML2 T−2] B. Surface Tension II. [ML2 T−1] C. Angular momentum III. [ML−1 T−1] D. Rotational kinetic energy IV. [ML0 T−2] (1) A-II, B-I, C-IV, D-III (2) A-I, B-II, C-III, D-IV (3) A-III, B-IV, C-II, D-I (4) A-IV, B-III, C-II, D-I

Q1. A physical quantity Q is found to depend on quantities a, b, c by the relation Q = a4b3 . The percentage error in c2 a, b and c are 3%, 4% and 5% respectively. Then, the percentage error in Q is: (1) 66% (2) 43% (3) 34% (4) 14%

Q1. If the percentage errors in measuring the length and the diameter of a wire are 0 . 1% each. The percentage error in measuring its resistance will be: (1) 0 . 2% (2) 0 . 3% (3) 0 . 1% (4) 0 . 144% Q2. 1 𝑏2 A force is represented by 𝐹= 𝑎𝑥2 + 𝑏𝑡 2, where 𝑥= distance and 𝑡= time. The dimensions of are : 𝑎 (1) [𝑀𝐿3 𝑇 – 3 ] (2) [𝑀𝐿𝑇– 2] (3) [𝑀𝐿– 1 𝑇– 1] (4) [𝑀𝐿2 𝑇– 3]

Q1. If two vectors →𝐴 and →𝐵 having equal magnitude 𝑅 are inclined at an angle 𝜃, then 𝜃 2𝑅sin (1) →𝐴− →𝐵= √2𝑅sin 𝜃2 (2) →𝐴+ →𝐵= 2 → → 𝜃 → → 𝜃 (3) 𝐴+ 𝐵= 2𝑅cos (4) 𝐴− 𝐵= 2𝑅cos 2 2

Q1. If mass is written as 𝑚= 𝑘𝑐𝑃𝐺-1 / 2 ℎ1 / 2, then the value of 𝑃 will be : (Constants have their usual meaning with 𝑘 a dimensionless constant) 1 1 (1) (2) 2 3 (3) 2 (4) -1 3