Question

Magnesium fluoride dissolves in water to the extent of 8.0 10-2 g/L at 25°C. Calculate the solubility of MgF2(s) in moles per liter, and calculate Ksp for MgF2 at 25°C.

I keep getting the same answer...please help!

Answer 1

It would have been far easier if you had posted your work, then I could have found the error.
MgF2 ==> Mg^2+ + 2F^-
solubility MgF2 = moles/L.
moles = 0.08/molar mass MgF2.
Ksp = (Mg^2+)(F2^-).
Substitute and solve for Ksp. Post your work if you still have trouble. The most common mistake made by students on a problem such as this is not multiplying MgF2 by 2 to obtain F^-, then not squaring the F^-.