[robertss]

 what influences the pH at equivalence point in a titration of a weak acid by a strong base?
All the acid has been neutralized, so does the conjugate base (A-) affect the pH? Or does the OH- affect it? I'm not sure I understand the rationale behind this. A short explanation would help me out. I've checked in my textbook but they merely have an explanation of how to do the calculations, not the rationale behind it.
Thanks!

[nj_bartel]

What is present in solution at equivalence point?

Is the conjugate base of a weak acid basic or acidic?

So how does the conjugate base react with water?

Does that mean the pH rises or lowers?

[robertss]

I'll just use acetic acid as an example.
At equivalence point HC₂H₃0₂ has been converted to H+ and C₂H₃O₂-. The H+ is canceled out by the base, so only C₂H₃O₂- is left.

I think I get where you're going: Would the conjugate base then react with water to form acetic acid and hydroxide? Thus, the pH would be dependent on hydroxide?
If so, the increased concentration of hydroxide would increase the pH of the solution.
Thanks!

[nj_bartel]

You got it