L1.2: Rate Law

• Rate Law

  Rate is expressed as a function of concentrations and temperature. The rate law is determined experimentally. Products do not appear in the rate law, so the rate depends only on reactant concentrations and temperature.
• Reaction Orders

  A reaction has an individual order “with respect to” or “in” each reactant. These are basically the exponent. For example, in a simple reaction A → products:

  • 1st order = If rate doubles, and [A] also doubles.
  • 2nd order = If rate quadruples, when [A] just doubles.
  • Zero order = If rate doesn’t change when [A] doubles, rate isn’t dependent on [A], and reaction is zero order with respect to A.