Yes, pH affects solubility. For ionic compounds containing basic anions, solubility is inversely proportional to pH – solubility increases as the pH of the solution decreases. In many sparingly soluble salts, the anion is the conjugate base of a weak acid. Protonation of the anion at low pH can increase the solubility of the salt dramatically. However, solubility is unaffected by pH changes in ionic compounds containing anions of negligible basicity such as the conjugate base of a strong acid.