[Boxxxed]

When pH=pKa

H⁺=Ka so H⁺+Ka=2H⁺

Disassociation of HF

HF+H2O<---->H3O⁺+F^-

ka=[H⁺][F^-]/[HF]

ka=2H⁺/H⁺= [H⁺][F^-]/[HF]

How do I farther simplify this to get the log of concentration of species [F-] in relation to pH?

I end up with log[F^-]=log2+log[HF]+pH

In the slides it says it should be a -log 2. Why is that?

[AWK]

This equation gives you the answer

HF+H2O<---->H3O++F-