A gaseous reaction occurs by a two-step mechanism,shown below.
Step 1: AX +Y₂ ⇌ AXY_{2 fast}
Step 2: AXY₂ + AX → 2 AXY slow
Including concentration of only reactants and products,what is the rate law for this reaction?

Question

Quizplus · Accepted Answer

The rate law is determined by the slow step, which is Step 2. The rate law for Step 2 is Rate = k[AXY₂][AX]. Since AXY₂ is in equilibrium with AX and Y₂ from Step 1, we can express [AXY₂] in terms of [AX] and [Y₂], leading to Rate = k[AX]²[Y₂].

A Gaseous Reaction Occurs by a Two-Step Mechanism,shown Below