Increasing the concentration of chemical reactants increases the reaction rate. But if the concentration of a reactant is doubled, does the reaction rate double, or might it quadruple? That depends on the reaction mechanism. Scientists vary the concentration of one reactant while holding another constant and measure the reaction rate. The data from these experiments generates a rate law. This PowerPoint presentation examines the general format of rate laws and explains how specific rate laws are determined. It also explains how to predict the effects of changes in reactant concentrations based on the rate law.