Chem II
posted by Ken on .
A 0.10 M HF solution is 8.4% ionized. Calculate the H^+ ion concentration.
Here is my line of thought. For every mole HF disolved yeilds one mole of H^+. Since there is ).10 M HF, and the solution is 8.4% ionized = 0.84 M. Is this correct?

I don't know where to start. First, you're line of thought is not quite correct.
1 mol HF dissolved will NOT yield 1 mol H^+ BECAUSE HF is not 100% ionized. That would be so if it were 100% (a strong acid but as you know, HF has a Ka of about 1 x 10^4). But your thinking is correct on the point that HF ionizes to yield H^+ and for every 1 mol HF that ionizes, the yield is 8.4% (0.084) or 1 x 0.084. So for 0.1, it would be just 0.1 x 0.084 =