Practice Questions

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

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

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

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 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 )

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.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.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.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______

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

Q73.When 81.0 g of aluminium is allowed to react with 128.0 g of oxygen gas, the mass of aluminium oxide produced in grams is_______ - (Nearest integer) Given : Molar mass of Al is 27.0 g mol−1 Molar mass of O is 16.0 g mol−1

Q73.During " S " estimation, 160 mg of an organic compound gives 466 mg of barium sulphate. The percentage of – Sulphur in the given compound is _______ %. (Given molar mass in gmol−1 of Ba : 137, S : 32, O : 16 )

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

Q74.Consider the following data : Heat of formation of CO2( g) = −393.5 kJ mol−1 Heat of formation of H2O(l) = −286.0 kJ mol−1 Heat of combustion of benzene = −3267.0 kJ mol−1 The heat of formation of benzene is _ kJmol−1 . (Nearest integer)

Q74.If 1 mM solution of ethylamine produces pH = 9, then the ionization constant (Kb) of ethylamine is 10−x . The value of x is ______ (nearest integer). [The degree of ionization of ethylamine can be neglected with respect to unity.]