Reactivity of solutions with the same anion

aekotra

If I have two aqueous solutions of two different compounds (with different solubility) that result in equal amounts of the same anion, should the anion in those solutions have the same reactivity or not?

An example:
Solution A
CaF₂ (aq)

Solution B
NaF (aq)

The solutions are prepared such that both contain the same amount of F^-. Is F^- more or less reactive in either of the solutions? Would it be dependent on the cations or solubility of the compound?

Borek

Before we will start to discuss details - what is your opinion? Per forum rules you should try to answer the question by yourself first.

aekotra

I'm leaning towards the idea that the reactivity would be different, perhaps due to the differing bond strengths in the compounds. Different cations in proximity to the anion would affect the anion's reactivity in ways particular to those species, despite both having been solvated.

Borek

Have you heard about ionic strength of the solution and activity coefficients? Debye-Hückel theory?

Alkim

CaF2 is practically insoluble in water.

Borek

Saturated CaF₂ is something like 4x10^-4 M in F^-. Not much, but quite a reasonable concentration, easy to prepare.