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 $p H$, acidic, basic, or neutral?

1 Answer
Feb 26, 2017

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

Explanation:

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

${\text{H"_3"CCH"_2"CO"_2^(-)"Na"^+ +"H"_2"O"rarr"H"_3"CCH"_2"CO"_2"H"(aq) + "Na"^+ +"HO}}^{-}$

And thus, with stoichiometric $\text{sodium propanoate}$ 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.