Will magnesium fluoride be more soluble in acidic solution?

1 Answer
Mar 30, 2017

Answer:

We assess the equilibrium:

#MgF_2(s) rightleftharpoons Mg^(2+) + 2F^-#

Explanation:

This site gives a #K_"sp"=5.16xx10^-11#. However, in acidic solution, we substantially reduce the concentration of one of the reagents that participates in the solubility expression, i.e. we modify #[F^-]#.

#F^-# is moderately basic (i.e. solutions of potassium fluoride gives rise to basic solutions), and would tend to be protonated in acidic solution. If we were willing to solve 2 equations in 2 unknowns, we could work out the solubility of #MgF_2# to a good approximation.

And thus #MgF_2# is expected to exhibit greater solubility in acidic solution.