posted by Christina .
The mineral CaF2 has a solubility of 2.1 x 10^-4 M. What is the Ksp of CaF2?
CaF2 ==> Ca^+2 + 2F^-
Ksp = (Ca^+2)(F^-)^2
You know solubility CaF2 = 2.1 x 10^-4; therefore, (Ca^+2) = 2.1 x 10^-4. Since (F^-) is twice that, (F^-) = 4.2 x 10^-4. Plug those values into the Ksp expression I wrote above and solve for Ksp. Post your work if you get stuck.