Question

A saturated solution of CaF2 (of MW 78.0
g/mol) contains 0.0167 grams per liter. What is the solubility product constant of CaF2?

Answer 1

..........CaF2 --> Ca^2+ + 2F^-
I.........solid....0........0
C.........solid....x........2x
E.........solid....x........2x

The easy way to do this is to convert g/L to mols/L and go from there.
mols/L = 0.0167/molar mass CaF2.
Then Ksp = (Ca^2+)(F^-)^2
Ksp = (x)(2x)^2 = 4x^3. You know what x is from above, solve for Ksp.