Answer: Straight line falling with time.
- A Curve rising with time
- B Exponential decay curve
- C Parabola through the origin
- D Straight line falling with time
Correct answer: D. Straight line falling with time
Explanation: A zero-order reaction follows [A] = [A]<sub>0</sub> - kt, which is a straight line of negative slope (-k) when concentration is plotted against 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.