Answer: s⁻¹.
- A s⁻¹
- B mol L⁻¹ s⁻¹
- C L mol⁻¹ s⁻¹
- D mol²
Correct answer: A. s⁻¹
Explanation: For first order, rate = k[A], so k has units of s⁻¹ (independent of concentration).
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.