reaction rate
The change in concentration of a recatant or product per unit time. Unit: mol/(L·s).
collision theory
States that atoms, ions, and molecules must collide in order to react.
activated complex
A temporary, unstable arrangement of atoms that may form products or may break apart to re-form the reactants.
transition state
The activated complex.
activation energy
The minimum amount of energy that reacting particles must have to form the activated complex and lead to a reaction. Represented by (E_a).
catalyst
A substance that increases the rate of a chemical reaction without itself being consumed in the reaction.
inhibitor
A substance that slows down, or inhibits, reaction rates.
heterogeneous catalyst
Exists in a physical state different than that of the reaction it catalyzes.
homogeneous catalyst
Exists in the same physical state as the reaction it catalyzes.
rate law
The equation that expresses the mathematical relationship between the rate of a chemical reaction and the concentration of reactants.
specific rate constant
A numerical value that relates reaction rate and concentration of reactants at a given temperature.
reaction order
Defines how the rate is affected by the concentration of that reactant.
method of initial rates
Determines reaction order by comparing the initial rates of a reaction carried out with varying reactant concentrations.
instantaneous rate
The rate of decomposition at a specific time.
complex reaction
A reaction that consists of two or more elementary steps.
reaction mechanism
The complete sequence of elementary steps that make up a complex reaction.
intermediate
A substance produced in one elementary step and consumed in a subsequent elementary step.
rate-determining step
The slowest of the elementary steps in a complex reaction.
