On the Existence and Uniqueness of the Equilibrium of Arbitrary Brønsted Acid–Base Mixtures

Because the calculation of the pH of arbitrary mixtures necessarily requires the application either of the proton-balance equation or of the charge-balance law, it may be rationalized by introducing the proton function, HF. The present article demonstrates that the HF of any Brønsted acid–base ideal mixture in aqueous medium is a monotonic decreasing function in the pH interval –1, 14 and that there is only one equilibrium condition.