Answer: time.
- A volume
- B time
- C mass
- D pressure
Correct answer: B. time
Explanation: Rate = change in concentration ÷ time, with units such as mol L⁻¹ s⁻¹.
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.