Relations between different rate expressions for a given reaction are derived directly from the stoichiometric coefficients of the equation representing the reaction Rate laws ( differential rate laws ) provide a mathematical description of how changes in the concentration of a substance affect the rate of a chemical reaction.

The rate of a chemical reaction is affected by several parameters. If temperature or reactant concentration is increased, the rate of a given reaction generally increases as well.

rate expression — mathematical representation defining reaction rate as change in amount, concentration, or pressure of reactant or product species per unit time. rate law — (also, rate equation) (also, differential rate laws) mathematical equation showing the dependence of reaction rate on the rate constant and the concentration of one or more…. given reaction — derived directly from the stoichiometric coefficients of the equation representing the reaction. catalyst — substance that increases the rate of a reaction without itself being consumed by the reaction.