Question

Suppose a saturated solution of barium fluoride contains 1.5 x 10 ^ -2 M of F-. What is the Ksp of BaF2.

I know that the balanced equation of this reaction is:

BaF2 (s) --> Ba2+ (aq) + 2F- (aq)

There is a 1:1 ratio between BaF2 and Ba2+ and there is a 1:2 ration between BaF2 and 2F-. I am unsure of how to work through this.

Answer 1

Ksp = (Ba^2+)(F^-)^2
You know (F^-) = 1.5E-2 M
You know (Ba^2+) = 1/2 the F^-
Plug those into Ksp expression and solve for Ksp.