The rate constant for the forward reaction: A(g) ⇌ 2B(g) is 1.5 × 10⁻³ s⁻¹ at 300 K. If 10⁻⁵ moles of 'A' and 100 moles of 'B' are present in a 10 litre vessel at equilibrium, then the rate constant o

Question

The rate constant for the forward reaction: A(g) ⇌ 2B(g) is 1.5 × 10⁻³ s⁻¹ at 300 K. If 10⁻⁵ moles of 'A' and 100 moles of 'B' are present in a 10 litre vessel at equilibrium, then the rate constant of the backward reaction at this temperature is

Prashant Kotian · Accepted Answer

Correct answer: C. Equilibrium concentrations: [A] = 10⁻⁵ / 10 = 10⁻⁶ M, and [B] = 100 / 10 = 10 M. The equilibrium constant K_c = [B]² / [A] = (10)² / 10⁻⁶ = 10⁸ M. Since K_c = k_f / k_b, we find k_b = k_f / K_c = (1.5 × 10⁻³) / 10⁸ = 1.5 × 10⁻¹¹ M⁻¹s⁻¹. Therefore, correct answer is C.

💡 Solution & Explanation

Practice 22,000+ questions like this