Titration+of+Vinegar+-+Prediction+Help+4

//**What do you expect the pH to be at the equivalence point?**//

Hint: I know what you are thinking, if the solution is neutralized the pH should be 7. Right and wrong. If you are neutralizing a strong acid and a strong base, then this assumption is correct. NaOH is a strong base, but is acetic acid a strong acid? No, it is not.

Think about conjugate acid-base pairs. When the neutralization occurs the strong base NaOH will have a weak conjugate acid. However, acetic acid is a weak acid and will have a strong conjugate base. Since at neutralization the pH will be determined by the presence of a weak acid and a strong base, the pH will not be 7. The pH will probably be around 5 or 9, which one is it?

BTW, a strong acid and strong base have a pH of 7 at their equivalence point because the conjugates present would be a weak acid and a weak base.

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