Question

The Ksp for calcium fluoride (CaF2) is 3.9 x 10^–11 at 25°C. How many moles of solid NaF must be added to 1.00 L of 0.100 M CaCl2 in order to precipitate CaF2?

Please help me set up this ICE table and understand how to solve this!! thank you!!

Answer 1

(Ca^2+) = 0.1M
Ksp = (Ca^2+)(F^-)2
Substitute 0.1M for Ca^2+ and solve for (F^-) in mols/L.
You have 1.00 L so that is the number of mols F^- (= mols NaF) that must be added.