Four silver salts, each having the general dissolution stoichiometry AgX(s) ⇌ Ag⁺(aq) + X⁻(aq), are listed with their measured solubility–product constants at 25 °C.
AgCl: 1.8×10−10
AgBr: 5.0×10−13
AgI: 8.3×10−17
AgCN: 1.2×10−8
A research chemist needs to prepare separate 0.010 M aqueous solutions of the anions Cl⁻, Br⁻, I⁻, and CN⁻ using the corresponding silver salts as the only available solids.
(a) Rank the four salts in order of increasing molar solubility when each is added in excess to pure water at 25 °C. Clearly indicate ties if any.
(b) Identify which, if any, of the salts could feasibly generate a 0.010 M solution of its anion under the stated conditions. Support your answer by relating the magnitude of Ksp to the concentration requirement.
(c) For the salt you judge most likely to meet the 0.010 M requirement, estimate its minimum molar solubility necessary to achieve that target concentration and comment on whether that minimum is consistent with the qualitative expectations from its Ksp. (A detailed numerical calculation of s is not required.)