The Ksp of calcium sulfate, CaSO4, is 9.1 × 10−6. What is the molar concentration of CaSO4 in a saturated solution?

Answer 1

...................CaSO4 ==> Ca^2+ + [SO4]^2-
I....................solid.............0..............0
C...................solid..............x.............x
E.....................solid.............x..............x
Ksp = 9.1E-6 = (Ca^2+)(SO4^2-)
Substitute the E like into the Ksp expression and solve for x = (Ca^2+) = solubility in moles/ L.