To determine the solubility of calcium sulfate CaSO4 in water at 25C, we can use the solubility product constant Ksp expression. The dissociation of CaSO4 in water can be represented as:CaSO4 s Ca aq + SO aq The Ksp expression for this reaction is:Ksp = [Ca][SO]Let the solubility of CaSO4 be represented by 's' mol/L. When CaSO4 dissolves, it produces 's' mol/L of Ca ions and 's' mol/L of SO ions. Therefore, we can substitute these concentrations into the Ksp expression:Ksp = s s = sNow, we can solve for 's' using the given Ksp value:4.93 10 = sTo find 's', take the square root of both sides:s = 4.93 10 s 7.02 10 mol/LSo, the solubility of calcium sulfate CaSO4 in water at 25C is approximately 7.02 10 mol/L.