Activity Coefficients

Calculations based on the concentrations of the chemical species are only the first approximation. The chemical and physical effects of a component are more accurately represented by the activityActivity of the species rather than its concentration. The activityActivity of a species incorporates all factors that may modify its concentration. It is possible to think either about the activityActivity as the “effective concentration” or the concentration as the first approximation to the activityActivity. The activity coefficientActivity coefficient is the factor that relates the concentration to the activityActivity.