This type of kinetics investigates the dependence of a reaction rate on the concentrations of reactants and/or catalysts, using the rate equation. Some common examples of reaction order kinetics are zero-order kinetics, first-order kinetics, and second-order kinetics. In zero-order kinetics, the reaction rate is independent of the concentration of the reactants, while in first-order kinetics, the rate is proportional to the concentration of a single reactant, and in second-order kinetics, the rate is proportional to the product of two reactant concentrations.