Question

25 mL of a 0.10 M solution of the weak acid hydrofluoric acid, HF, (Ka = 7.2 x 10-4) is titrated with a 0.10 M solution of the weak base ammonia, NH3 (Kb = 1.8 x 10-5). Will the pH at the equivalence point be less than 7, equal to 7, or greater than 7? Explain.

I’m guessing it’s going to be less than 7 because the greater amount of H+ produced from HF since Ka is greater? Or is that wrong??
Or maybe it would be equal to 7 since that's the place where the two are equal??

Answer 1

THe pH at equivalence point is always 7

Answer 2

Wrong^
The eq. point will be below 7 because the Ka is greater than the Kb --> [H+] is greater than [OH-].