Since equation (1) represents an equilibrium, a relationship between the concentrations can be derived. This relationship can be expressed as
where is the solubility product constant and the bracketed quantities are the concentrations of the respective ions. The solubility product constant has the same value under constant conditions; however, its value changes when conditions such as temperature change. The general form for the representation of is that the concentration of each ion is raised to a power equal to the number of ions of that type in the molecular formula. For example, for the equation
