If 15% of a O.1 M solution of a weak acid dissociates into H+ and A- ions, what is the concentration of H3O+? (HA + H2O --> H3O+ + A-) ?

1 Answer
May 3, 2018

Would it not be 0.015molL1 with respect to H3O+?

Explanation:

And so we should address the equilibrium...

HA(aq)+H2O(l)H3O++A

Initially, [HA]=0.1molL1...finally...[H3O+][A]0.015molL1...and [HA]0.10.015, and we could work out Ka from these data...

Ka=[H3O+][A][HA]=0.015×0.0150.10.015=2.65×103...