A rate law is an equation that relates the rate of a chemical reaction to the concentration of its reactants. It is expressed in the form: rate = k[A]^m[B]^n, where k is the rate constant, A and B are the concentrations of the reactants, and m and n are the reaction orders. The values of m and n indicate how the rate changes with varying concentrations. The rate law helps chemists understand how different factors affect reaction speed. It is determined experimentally and can vary for different reactions. By analyzing the rate law, scientists can predict how changes in concentration or temperature will influence the reaction, aiding in the design of chemical processes.