Question

why

Answer 1

To summarise

Question http://prntscr.com/9uqhq7
My work http://imgur.com/VXpRrAI
WolframAlpha http://goo.gl/oeffmu

The answer seems to be wrong though

Answer 2

@abb0t
@Zale101

Answer 3

pH = -log[H]
so if you have pH = P,
that must mean, -log[H] = P

Is what i am sort of seeing righ tnow.

Answer 4

Also, HF is not a strong acid, it does not completely dissociate.

Answer 5

and also, HF is stronger, in this case, than acetic acid.

Answer 6

Yeah, I've kept all of that in mind during the calculations. I get pH = 5.17...