Chapter 17, Problem 115SCQ

Interpretation Introduction

Interpretation:

The reason for increased solubility of ${\text{Ag}}_{\text{3}}{\text{PO}}_{\text{4}}$ in water than the value of its solubility calculated using $K_{\text{sp}}$ value has to be explained.

Concept introduction: The solubility of insoluble salts containing anions (conjugate base of a weak acid) such as hydroxide, acetate, carbonate, phosphate, and sulfide is greater than the value calculated using $K_{\text{sp}}$ value. This is because the anion undergoes hydrolysis that is it reacts with water (acid-base reaction). This decreases the concentration of the anion in the solution and as result the reaction equilibrium shifts to right-hand side or become product favored. Thus the solubility of the salt increases.