precipitation?

Question

A solution is prepared by dissolving 1.6 g of SrCrO4 in 100. mL of hot water. SrCrO4 dissolves according to the equation

SrCrO4 -> Sr 2+ + CrO4 2-

Should a precipitate form if the solution is cooled to 25 C? Assume that a negligible change in volume occurs during the process. (Ksp=3.6 x 10^-5)

Answer 1

Divide 1.6 by the Mr of SrCrO4 and multiply it my 10 to get its molarity, and see whether this is greater of less than the square root of the Ksp value. If it's greater, you will get a precipitate.