Acid base reactions can affect solubility. Suppose you study the solubility of CaCO3 in water, or in buffers of various hydrogen ion concentration. (A buffer is a solution containing mixtures of acids and bases designed to maintain a hydrogen ion concentration that is nearly constant. pH is a measure of [H+]. [H+] = 10-pH.
In a slightly acidic solution, for example, carbonate is converted into bicarbonate. Since bicarbonate salts usually are soluble, this leads to increased solubility.
