Answer: s⁻¹.
- A mol L⁻¹ s⁻¹
- B L mol⁻¹ s⁻¹
- C s⁻¹
- D L² mol⁻² s⁻¹
Correct answer: C. s⁻¹
Explanation: For first-order reactions, k has units of s⁻¹ (reciprocal time).
First-order decay curve: concentration halves every t½, and that half-life is constant - a defining test for first-order kinetics.
Concept context
Study the speed of reactions and what affects it: concentration, temperature, and catalysts. Covers rate law, order of reaction, the Arrhenius equation, and reaction mechanisms step by step.