[dpsguy]

 How does the solubility of salts depend on pH? For example , would the solubility of CaF2 increase or decrease if the pH of its solution were decreased? Is their a mathematical expression for this?

[Borek]

How does the solubility of salts depend on pH? For example , would the solubility of CaF2 increase or decrease if the pH of its solution were decreased? Is their a mathematical expression for this?

Hydrofluoric acid - strong, or weak?

What will happen to the F^- anions in acidic solution?

Ca²⁺ - what will it do in the presence of OH^-?

Le Chateliers Principle?

It can be all calculated using individual equilibrium equations. There is no one, universal method of calculations, unless you want to try numerical methods.