AIPMT-MAINS Chemistry Questions

Given that the equilibrium constant for the reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) has a value of 278 at a particular temperature. What is the value of the equilibrium constant for the following reaction at the same temperature? SO₃(g) ⇌ SO₂(g) + 1/2 Ω₂(g)

Structure of a mixed oxide is cubic close-packed (c.c.p). The cubic unit cell of mixed oxide is composed of oxide ions. One fourth of the tetrahedral voids are occupied by divalent metal A and the octahedral voids are occupied by a monovalent metal B. The formula of the oxide is:

Given the reaction between 2 gases represented by A₂ and B₂ to give the compound AB(g). A₂(g) + B₂(g) ⇌ 2 AB(g). At equilibrium, the concentration of A₂ = 3.0 × 10⁻³ M, B₂ = 4.2 × 10⁻³ M, and AB = 2.8 × 10⁻³ M. If the reaction takes place in a sealed vessel at 527°C, then the value of Kc will be:

Activation energy (Eₐ) and rate constants (k₁ and k₂) of a chemical reaction at two different temperatures (T₁ and T₂) are related by:

During change of O₂ to O₂⁻ ion, the electron adds on which one of the following orbitals?

Standard reduction potentials of the half reactions are given below: F₂(g) + 2e⁻ → 2F⁻ (aq) ; E° = +2.85 V Cl₂(g) + 2e⁻ → 2Cl⁻ (aq) ; E° = +1.36 V Br₂(l) + 2e⁻ → 2Br⁻ (aq) ; E° = +1.06 V I₂(s) + 2e⁻ → 2I⁻ (aq) ; E° = +0.53 V The strongest oxidising and reducing agents respectively are:

A certain gas takes three times as long to effuse out as helium. Its molecular mass will be:

The orbital angular momentum of a p-electron is given as:

Vapour pressure of chloroform (CHCl₃) and dichloromethane (CH₂Cl₂) at 25°C are 200 mm Hg and 41.5 mm Hg respectively. Vapour pressure of the solution obtained by mixing 25.5 g of CHCl₃ and 40 g of CH₂Cl₂ at the same temperature will be: (Molecular mass of CHCl₃ = 119.5 u and molecular mass of CH₂Cl₂ = 85 u).

Molar conductivities (Λ°) at infinite dilution of NaCl, HCl and CH₃COONa are 126.4, 425.9 and 91.0 S cm² mol⁻¹ respectively. Λ° for CH₃COOH will be:

For real gases van der Waals equation is written as \( \left( p + \frac{an^2}{v^2} \right) (V - nb) = nRT \) where 'a' and 'b' are van der Waals constants. Two sets of gases are: (I) Ω₂, CO₂, He and (II) CH₄, O₂, H₂. The gases given in set-I in increasing order of 'b' and gases given in set-II in decreasing order of 'a', are arranged below. Select the correct order from the following:

Red precipitate is obtained when ethanol solution of dimethylglyoxime is added to ammoniacal Ni(II). Which of the following statements is not true?

Low spin complex of d⁶-cation in an octahedral field will have the following energy: (Δ₀ = Crystal Field Splitting Energy in an octahedral field, P = Electron pairing energy)

Which one of the following does not correctly represent the correct order of the property indicated against it?

Four successive members of the first series of the transition metals are listed below. For which one of them the standard potential (E°_{M²⁺/M}) value has a positive sign?

In the replacement reaction RCl + MF → RF + MCl The reaction will be most favourable if M happens to be:

In which of the following arrangements the given sequence is not strictly according to the property indicated against it?

Four diatomic species are listed below. Identify the correct order in which the bond order is increasing in them:

The catalytic activity of transition metals and their compounds is ascribed mainly to:

Which of the following exhibit only +3 oxidation state?

The Gibbs' energy for the decomposition of Al₂O₃ at 500°C is as follows: \( \frac{2}{3} \text{Al}_2\text{O}_3 \rightarrow \frac{4}{3} \text{Al} + \text{O}_2 ; \Delta G = +960 \text{kJ mol}^{-1} \) The potential difference needed for the electrolytic reduction of aluminium oxide (Al₂O₃) at 500°C is at least:

Chloramphenicol is an:

Consider the following reaction: ![Diagram showing reaction: Benzoyl chloride (C₆H₅COCl) with H₂ and Pd⁻BaSO₄ to form 'A'] The product 'A' is:

Which one of the following sets forms the biodegradable polymer?

An organic compound (C₃H₉N) (A), when treated with nitrous acid, gave an alcohol and N₂ gas was evolved. (A) on warming with CHCl₃ and caustic potash gave (C) which on reduction gave isopropylmethylamine. Predict the structure of (A).

Which of the following reagents will be able to distinguish between¹⁻butyne and²⁻butyne?

Consider the reaction: RCHO + NH₂NH₂ → RCH = N–NH₂ What sort of reaction is it?

Which of the following compounds will give a yellow precipitate with iodine and alkali?

Which of the following compounds can be used as antifreeze in automobile radiators?

For its activity, carboxypeptidase requires:

In gobar gas, the maximum amount is that of:

Which one of the following biomolecules is correctly characterised?

"Good ozone" is found in the

Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model?

Match list-I with List-II for the composition of substances and select the correct answer using the code given below the lists

Which of the following statements is incorrect? (1) Aluminium reacts with excess NaOH to give Al(OH)₃ (2) NaHCO₃ on heating gives Na₂CO₃ (3) Pure sodium metal dissolves in liquid ammonia to give blue solution (4) NaOH reacts with glass to give sodium silicate

Which of the statements about "Denaturation" given below are correct? Statements : (a) Denaturation of proteins causes loss of secondary and tertiary structures of the protein (b) Denaturation leads to the conversion of double strand of DNA into single strand (c) Denaturation affects primary structure which gets distorted

The IUPAC name of the following compound is

Which of the following oxide is amphoteric?

Which of the following compounds undergoes nucleophilic substitution reaction most easily?

An organic compound 'A' on treatment with NH₃ gives 'B' which on heating gives 'C' when treated presence of KOH produces ethylamine. Compound with Br in the 'A' is

A 0.1 molal aqueous solution of a weak acid is 30% ionized. If Kf for water is 1.86°C/m, the freezing point of the solution will be

The following reactions take place in the blast furnace in the preparation of impure iron. Identify the reaction pertaining to the formation of the slag.

In qualitative analysis, the metals of group I can be separated from other ions by precipitating them as chloride salts. A solution initially contains Ag⁺ and Pb²⁺ at a concentration is 0.10 M. Aqueous HCl is added to this solution until the Cl⁻ concentration is 0.10 M. What will the concentration of Ag⁺ and Pb²⁺ be at equilibrium? (Ksp for AgCl = 1.8 × 10⁻¹⁰, Ksp for PbCl₂ = 1.7 × 10⁻⁵)

Which of the following structures is the most preferred and hence of lowest energy for SO₃?

The unit of rate constant for a zero order reaction is

A solution contains Fe²⁺, Fe³⁺ and I⁻ ions. This solution was treated with iodine at 35°C. E° for Fe³⁺/Fe²⁺ is +0.77 V and E° for I₂/2I⁻ = 0.536 V. The favourable redox reaction is

200 mL of an aqueous solution of a protein contains its 1.26 g. The Osmotic pressure of this solution at 300 K is found to be 2.57 × 10⁻³ bar. The molar mass of protein will be (R = 0.083 L bar mol⁻¹ K⁻¹)

The rate of the reaction 2N₂O₅ → 4NO₂ + O₂ can be written in three ways: -d[N₂O₅]/dt = k[N₂O₅], d[NO₂]/dt = k'[N₂O₅], d[O₂]/dt = k''[N₂O₅]. The relationship between k and k' and between k and k'' are

The half life of a substance in a certain enzyme-catalysed reaction is 138 s. The time required for the concentration of the substance to fall from 1.28 mg L⁻¹ to 0.04 mg L⁻¹ is