The rate-determining step is the slowest elementary step in a reaction mechanism, and it governs the overall rate of the reaction. Because it has the highest activation energy, it acts as a bottleneck through which the whole reaction must pass. The rate law of the overall reaction is therefore determined by this step.

决速步骤是反应机理中最慢的基元步骤,它支配反应的总速率。由于它具有最高的活化能,它如同整个反应必须通过的瓶颈。因此,总反应的速率定律由这一步骤决定。