Two insoluble silver salts are examined at 25 °C. Their published solubility-product constants are identical: Ksp=1.8×10−10 for each of the following compounds.
• Silver chloride, AgCl
• Silver chromate, Ag2CrO4
Assume the only process that limits dissolution is the establishment of the heterogeneous equilibrium between solid and its ions in pure water.
(a) Write the balanced chemical equation for the dissolution of each salt in water and the corresponding algebraic expression for Ksp in terms of molar solubility s.
(b) Without substituting numbers, compare the algebraic relationships obtained in part (a) and explain, on the basis of stoichiometry, which salt will have the greater molar solubility.
(c) Describe qualitatively how the stoichiometric coefficients in a dissolution equilibrium influence the numerical relationship between Ksp and molar solubility.