Chemistry

Problem

Calcium fluoride, CaF2(s), has

K_{sp}=3.9\times10^{-11}

at 25 °C. The acid dissociation constant for hydrofluoric acid is

K_a=6.6\times10^{-4}

. What pH must a solution have so that the molar solubility of CaF2 is exactly

1.0\times10^{-3}\,\text{M}