JEE Chemistry - MCQ Practice Questions

A weak acid HA has Ka = 1.8 × 10⁻⁵. What is the pH of a 0.2 M solution of HA?

Which statement correctly describes the relationship between Gibbs free energy and equilibrium constant?

An ideal gas undergoes isothermal expansion from 2 L to 8 L at 300 K. Calculate the entropy change if n = 1 mol.

The solubility product (Ksp) of AgCl at 25°C is 1.8 × 10⁻¹⁰. What is the solubility in mol/L?

A buffer solution is prepared by mixing 100 mL of 0.1 M acetic acid (Ka = 1.8 × 10⁻⁵) with 50 mL of 0.1 M NaOH. What is the pH?

Which of the following represents a second-order reaction with respect to reactant A?

A galvanic cell is constructed using Zn/Zn²⁺ (E° = -0.76 V) and Cu/Cu²⁺ (E° = +0.34 V) electrodes. What is the standard cell potential?

For a reaction mechanism with a rate-determining slow step, which statement is correct?

The rate constant for a reaction doubles when temperature increases from 27°C to 37°C. What is the activation energy (Ea) for this reaction? (Given: R = 8.314 J/mol·K)

The decomposition of H₂O₂ follows first-order kinetics with k = 1.4 × 10⁻³ min⁻¹. What is the half-life of H₂O₂?

A reaction mechanism consists of: Step 1 (slow): A + B → C; Step 2 (fast): C + D → E. The overall reaction is A + B + D → E. What is the rate law?

For the equilibrium: H₂(g) + I₂(g) ⇌ 2HI(g), Kc = 50 at 400°C. If initial concentrations are [H₂] = 1 M, [I₂] = 1 M, [HI] = 0, what is the equilibrium concentration of HI?

What is the coefficient of x in the van 't Hoff equation: d(ln Kp)/dT = ΔH°/RT²?

The standard entropy change (ΔS°) for a reaction is -150 J/mol·K and ΔH° = -200 kJ/mol. Below what temperature will this reaction be spontaneous?

Using Nernst equation at 25°C, if E°cell = 1.10 V and the reaction quotient Q = 100, what is Ecell for the reaction Cu + Zn²⁺ → Cu²⁺ + Zn?

What is the charge (in Coulombs) required to deposit 1 mole of Al from Al³⁺?

For a weak acid HA with Ka = 1.8 × 10⁻⁵, what is the pH of a 0.1 M solution?

A buffer is prepared by mixing 100 mL of 0.2 M acetic acid with 100 mL of 0.2 M sodium acetate. What is the pH? (Ka of acetic acid = 1.8 × 10⁻⁵)

The solubility product (Ksp) of CaCO₃ is 3.3 × 10⁻⁹. What is the solubility of CaCO₃ in water?

A complex ion [Fe(CN)₆]³⁻ has a coordination number of 6. What is the oxidation state of Fe?