General Kinetic Rules for Chemical Reactions

Abstract

The rate of a chemical reaction is determined by the changes in concentrations of the reactants (or of reaction products) with time. The concentration is usually measured by the number of moles of the given species per unit volume, i.e. by the value c = N/V mol/cm³ (N is the number of moles, V is the volume in cm³) or by the number of molecules per unit volume (number density) n = cN_A molecule/cm³, where N_A = 6.02 · 10²³ molecules per mole is the Avogadro number. Sometimes the concentration is measured by the mass of the species per unit volume in grams, i.e. by the species density ρ = mn (m is the molecular mass) and also by partial pressure p = nkT = (ρ/m) kT.