Posted by Saira on .
A 0.040M solution of a monoprotic acid is 14% ionized. Calculate the Ka for the weak acid.

so:
HX <> H+ + X
Ka= [H+][X]/ [HX]
Since its a monoprotic acis i know the concentration of H and X will be equal
And the HX will be 86% (100%14%)
BUt i m not sure how to solve for it

Chemistry 
DrBob222,
So (H^+) = 0.04 x 0.14 = ??
(X^) is the same.
(HX) = either,
0.04(0.04*0.14) OR
0.04*0.86 (HX) will be the same no matter which way you go.