Question

Calcium fluoride (CaF2) is a slightly soluble salt, which dissociates in water according to the following reaction:

CaF2(s) ⇌ Ca2+(aq) + 2F–(aq)

What is the solubility product constant for this reaction?

Answer 1

Is the solution saturated with CaF2. I will assume so.

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

Ksp = (Ca^2+)(F^-)^2
Ksp = (x)(2x)^2 but if you're looking for a number you can't get it without know EITHER Zn ion or F ion. I suspect you just didn't type that in when you posted. Or perhaps you're supposed to look it up on Google.