<Dd> ∫ μ ∘ μ d μ = ∫ P ∘ P V _̄ d P (\ displaystyle \ int _ (\ mu ^ (\ circ)) ^ (\ mu) (d \ mu) = \ int _ (P ^ (\ circ)) ^ (P) ((\ bar (V)) dP)) </Dd> <P> Now, for an ideal gas: </P> <Dl> <Dd> V _̄ = R T P (\ displaystyle (\ bar (V)) = (\ frac (RT) (P))) </Dd> </Dl> <Dd> V _̄ = R T P (\ displaystyle (\ bar (V)) = (\ frac (RT) (P))) </Dd>

Compared to the fugacity of pure water the fugacity of water in a saline solution will be