Chemistry Problem Solving Videos @ WVU

Chem 116 - General Chemistry II

Selective Precipitation - Video Solution

A solution is 8.8×10-4 M in Th4+, Ca2+, and Li+. As NaF is slowly added to this solution, what [F-] is needed to precipitate as much of the Th4+ as possible without precipitating either the Li+ or the Ca2+?

Salt Ksp
ThF4 5.0x10-29
CaF2 3.2x10-11
LiF 1.7x10-3

What [F-] is needed to precipitate as much Th4+ and Ca2+ without precipitating the Li+?

At this [F-], what concentration of Th4+ and Ca2+ are left in solution and what percent of these ions have been precipitated?

Video B59