Reaction order is the power to which a reactant's concentration is raised in the rate law, and the overall order is the sum of these powers for all reactants. It indicates how strongly the rate depends on each concentration. The order must be determined experimentally and is not necessarily related to the stoichiometric coefficients.

反应级数是速率定律中某反应物浓度所取的幂,而总级数是所有反应物这些幂之和。它表明速率对各浓度依赖的强弱。级数必须由实验确定,且不一定与化学计量系数相关。