• Chemical Kinetics - The study of the rates of chemical reactions.
• Rate of a Reaction - The change in concentration of one of the reactants (DX), during a given period of time (Dt)

• The reaction rate gradually decreases as reactants are consumed.
  • Instantaneous Rate of Reaction - The rate of a reaction at an instant in time.

where d(X)/dt is the derivative X/t in terms of t.

• Rate Law - An equation that describes how the rate of a chemical reaction depends on the concentrations of the reactants consumed in that reaction.

rate = k[O₃]

• Rate Constant (k) - The proportionality constant in the rate law equation that describes the relationship between  the rate of a step in a chemical reaction and the product of the concentrations of the reactants consumed in that step.

**The rate law for a reaction cannot be determined by the coefficients of the balanced reaction; it must be determined experimentally.

For gas equilibrium equations, the equilibrium constant (K_c) is equal to the rate constant for the forward reaction divided by the rate constant of the reverse reaction.

See Sample Rate Calculations

For the reaction:

where a, b, c, d are the coefficients for the reactants and products A, B, C, D

Next:  "Order and Molecularity"