00:01
For this question, we have a solution that contains the salt, potassium fluoride.
00:06
Potassium is a cation that we could think of as having come from the strong base potassium hydroxide.
00:14
Therefore, it does nothing to affect the ph of the solution.
00:18
However, fluoride did not come from a strong acid, so it is a significant weak base, it having come from the weak acid, hydrofluoric acid.
00:26
So to solve for the ph of this solution and all the other concentrations, we need to know the pkb of fluoride.
00:36
To calculate the pkb of fluoride, we divide the kb of fluoride, we calculate this by dividing ka of hydrofluic acid into kw, and we get 1 .47 times 10 of the negative 11 as the kb for fluoride...