A .10 M Pb(NO3)2 solution has hydrofluoric acid, HF, added to it until [HF] = .10 M?

Question

a. Does PbF2 precipitate from this solution? Ksp PbF2 = 3.7 * 10^-8 and Ka HF = 7.2 * 10 ^-4
b. What is the minimum pH at which PbF2 precipitates?

Answer 1

a) Yes

b) 4.56