To find 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 Let the solubility of CaSO4 be represented by s in mol/L. When CaSO4 dissolves, it produces 1 mol of Ca ions and 1 mol of SO ions for each mole of CaSO4 that dissolves. Therefore, the concentration of Ca ions and SO ions will also be s mol/L.The Ksp expression for CaSO4 is:Ksp = [Ca] [SO]Since the concentrations of Ca and SO ions are both s, we can rewrite the Ksp expression as:Ksp = sNow, we can plug in the given Ksp value of 4.93 10 and solve for s:4.93 10 = sTo find s, take the square root of both sides:s = 4.93 10 s 7.02 10 mol/LTherefore, the solubility of calcium sulfate in water at 25C is approximately 7.02 10 mol/L.