1. The problem statement, all variables and given/known data How many moles of solid sodium fluoride should be added to 1.0 L of a saturated solution of barium fluoride, BaF2, at 25OC to raise the fluoride concentration to 3.0 x 10-2 mol/L? The solubility product constant for BaF2 is Ksp = 1.7 x 10-6 at 25OC. 3. The attempt at a solution BaF2 ---> Ba2+ + 2F- Initial Concentrations: 0, 0 Change: + x, + 2x Therefore: 1.7 x 10-6 = x(2x)2 x = 0.00752 M. So: [F-] = 0.01504 mol/2 L. I thought to have the desired fluoride concentration, only 1.5 x 10-2 mol would need to be added. However, the correct answer is Spoiler 2.6 x 10-2 mol . Thank you for your help!