Asked by Edward

Given the following acid-dissociation constants, which acid has the strongest conjugate base?

A. CH3COOH Ka = 1.8 * 10^-5
B. HCN Ka = 6.2 * 10^-10
C. HOCl Ka = 3.0 * 10^-8
D. HIO3 Ka = 0.17

I'm not really sure how to approach this problem. Can someone please help me out.
Answered by DrBob222
The bottom line is that the strongest acid has the weakest conjugate base or the weakest acid will have the strongest conjugate base. The weakest acid must be HCN so CN^- should be the strongest base.
If you go another route, you can calculate Kb.
Kb = Kw/Ka. You can calculate Kb for each of the acids listed. You see that plugging in the smallest value for Ka gives you the largest base.
Answered by Edward
So would you say that B is the correct answer.
Answered by DrBob222
yes
Answered by Kattrina
B. HCN Ka = 6.2 * 10^-10
just took the test
There are no AI answers yet. The ability to request AI answers is coming soon!