what is meant by the rate of a reaction? the rate of a reaction what is meant by the rate of a reaction?the rate of a reaction indicates how fast the products are formed or how fast the reactants are consumed. is the number of collisions between the molecules of reactants per unit of time. is the difference between the rate of formation of the products and the rate of disappearance of the reactants. indicates what amount of product can be obtained from the given amount of reactant.