[John]

HI,
I've been asked to find, "what volume of NaOH (in equivalents) is needed to be added so that there are equal amounts of associated and disassociated forms of this acid in solution?"


A graph was made with pH on the Y-axis and ml of [OH-] on the x-axis, the inflection point was was found at pH=4.76  and 40.00 ml of [OH-]. Im not sure if the question is simple asking for the point where the dissociable [H+]   ions and the associable [OH- ] ions  have reached 50% equivalence or .5 
Where,
40ml = .5 equivalent
pH = 4.76 + log [.5/.5]

or something like equivalent/L
Any ideas?

[Borek]

I believe they are looking for [HA] = [A^-].