Three crystalline salts are listed below with their experimentally determined solubility–product constants, all measured at 25 °C.
Salt A: Ksp=1.5
Salt B: Ksp=2.7×10−5
Salt C: Ksp=9.1×10−10
Assume each salt has the same simple 1:1 ion dissociation stoichiometry (for example, MX ⇌ M⁺ + X⁻). Answer the following about their behavior when each solid is added in excess to pure water at 25 °C.
(a) For each salt, state whether it is expected to be classified as soluble, sparingly soluble, or effectively insoluble in water. Base your classification on the magnitude of the given Ksp value and provide a brief justification.
(b) Describe qualitatively how the position of the dissolution equilibrium differs between Salt A and Salt C. In your explanation, refer to relative ion concentrations in the saturated solutions and the extent to which each solid phase remains undissolved.
(c) Suppose the saturated solution of Salt B is carefully filtered and then evaporated to dryness. Predict whether a visually observable mass of solid would be recovered after evaporation and explain the chemical reasoning behind your prediction.