Practice Questions

Q68.For a Mg Mg2+(aq) Ag+(aq) Ag the correct Nernst Equation is : [Ag+] [Ag+]2 (1) (2) Ecell = Eocell −RT2 F ln [Mg2+] Ecell = Eocell + RT2 F ln [Mg2+] (3) [Ag+]2 (4) [Mg2+] cell −RT2 F ln [Ag+] Ecell = Eocell −RT2 F ln [Mg2+] Ecell = Eo

Q68.The large difference between the melting and boiling points of oxygen and sulphur may be explained on the basis of (1) Atomicity (2) Electron gain enthalpy (3) Electronegativity (4) Atomic size

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.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.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.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.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)

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.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.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.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.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.Given below are two statements : Statement (I): In partition chromatography, stationary phase is thin film of liquid present in the inert support. Statement (II) : In paper chromatography, the material of paper acts as a stationary phase. 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) Statement I is false but Statement II is true (3) Both Statement I and Statement II are false (4) Both Statement I and Statement II are true

Q69.Consider the given plots of vapour pressure (VP) vs temperature(T/K). Which amongst the following options is correct graphical representation showing ΔTf , depression in the freezing point of a solvent in a solution? (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.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 .

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.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.Consider ' n ' is the number of lone pair of electrons present in the equatorial position of the most stable structure of ClF3 . The ions from the following with ' n ' number of unpaired electrons are A. V3+ B. Ti3+ C. Cu2+ D. Ni2+ E. Ti2+ Choose the correct answer from the options given below: (1) A and C Only (2) A, D and E Only (3) B and D Only (4) B and C 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

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.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.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).

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