Rate equations

Definition

Rate equations are mathematical expressions that describe the rate of a chemical reaction as a function of the concentration of reactants. They help determine the speed at which reactants convert to products.

5 Must Know Facts For Your Next Test

1. Rate equations often take the form $rate = k[A]^m[B]^n$, where $k$ is the rate constant and $m$ and $n$ are the reaction orders.
2. The overall order of a reaction is the sum of the exponents in its rate equation.
3. Units of the rate constant $k$ vary depending on the overall order of the reaction.
4. Rate equations can be determined experimentally through methods like initial rates or integrated rate laws.
5. Zero-order, first-order, and second-order reactions each have distinct forms for their rate equations.

Review Questions

• What is a rate equation and what does it describe?
• How do you determine the overall order of a reaction from its rate equation?
• What experimental methods can be used to determine a rate equation?

Related terms

Rate Constant: A proportionality constant, denoted as $k$, in the rate equation, which is specific to a given reaction at a specific temperature.

Reaction Order: The exponent to which a reactant concentration is raised in a rate equation, indicating how the rate is affected by changes in that concentration.

Integrated Rate Law: An expression that shows how concentrations of reactants change over time, derived from integrating the differential form of the rate law.