Question

At the endpoint of a titration of sodium acetate......will solution `pH` be at `7` or greater or lower than `7`?

Sodium acetate is titrated with hydrochloric acid. At the endpoint, what will be solution `pH`, acidic, basic, or neutral?

Answer 1

At the endpoint, you have a solution that is stoichiometric in `"H"_3"CCH"_2"CO"_2^(-)"Na"^+`. Agreed?

Explanation:

However, as the conjugate base of a WEAK acid, this should engage in an acid-base equilibrium with the water solvent:

`"H"_3"CCH"_2"CO"_2^(-)"Na"^+ +"H"_2"O"rarr"H"_3"CCH"_2"CO"_2"H"(aq) + "Na"^+ +"HO"^(-)`

And thus, with stoichiometric `"sodium propanoate"` the solution should be SLIGHTLY basic due to this hydrolysis reaction. Fluoride salts, the salts of a weak acid, give slightly alkaline solutions for this same reason.

Most of the common acid base indicators, however, will give good consistent results for this titration.