<Dl> <Dd> (∂ ln ⁡ N i ∂ P) T = − V i, a q − V i, c r R T (\ displaystyle \ left ((\ frac (\ partial \ ln N_ (i)) (\ partial P)) \ right) _ (T) = - (\ frac (V_ (i, aq) - V_ (i, cr)) (RT))) </Dd> </Dl> <Dd> (∂ ln ⁡ N i ∂ P) T = − V i, a q − V i, c r R T (\ displaystyle \ left ((\ frac (\ partial \ ln N_ (i)) (\ partial P)) \ right) _ (T) = - (\ frac (V_ (i, aq) - V_ (i, cr)) (RT))) </Dd> <P> where the index i iterates the components, N is the mole fraction of the i component in the solution, P is the pressure, the index T refers to constant temperature, V is the partial molar volume of the i component in the solution, V is the partial molar volume of the i component in the dissolving solid, and R is the universal gas constant . </P> <P> The pressure dependence of solubility does occasionally have practical significance . For example, precipitation fouling of oil fields and wells by calcium sulfate (which decreases its solubility with decreasing pressure) can result in decreased productivity with time . </P>

Is determined by the number of particles of a substance in a solution