Question

The rate of formation of a dimer in a second order dimerisation reaction is 6.5 × 10⁻⁶ mol L⁻¹s⁻¹ at 0.01 mol L⁻¹ monomer concentration. Calculate the rate constant.

Answer 1

Given:

Rate of formation of dimer = 6.5 × 10⁻⁶ mol L⁻¹s⁻¹

Monomer concentration = 0.01 mol L⁻¹

The reaction is second order (dimerisation: 2A → A₂), so:

Rate = k[A]²

⇒ 6.5 × 10⁻⁶ = k × (0.01)²

⇒ 6.5 × 10⁻⁶ = k × 1 × 10⁻⁴

⇒ k = `(6.5 xx 10^-6)/(1 xx 10^-4)`

⇒ k = 6.5 × 10⁻² L mol⁻¹s⁻¹