Reaction Mechanisms and Rate Law

AP Chemistry· difficulty 3/5

A reaction A + B → C is proposed to proceed by mechanism: (i) A + A ⇌ A₂ fast; (ii) A₂ + B → 2C slow.

(i) A + A ⇌ A₂ (fast eq, K) (ii) A₂ + B → 2 C (slow, k₂) [A₂] = K[A]²

What is the predicted rate law?

  • A

    rate = k[A₂][B]

  • B

    rate = k[A]²[B]

    check_circle
  • C

    rate = k[A][B]

  • D

    rate = k[A][B]²

Explanation

The slow step gives rate = k₂[A₂][B]. Substituting [A₂] = K[A]² gives rate = k₂K[A]²[B] = k[A]²[B].

Want 10 more like this — adaptive to your weak spots?

Related questions