Question

From the options below, choose the major species present in your titration's reaction flask beyond the equivalence point (i.e. at the end of the titration). Include spectator ions. (you can choose more than one) (NaOH and acetic acid)

H+
Na+
HAc
OH-
Ac-

Answer 1

Beyond the equivalence point of a titration with acetic acid and NaOH, the major species in the solution include sodium ions (Na+) as spectator ions, excess hydroxide ions (OH-), and acetate ions (Ac-).

Step-by-step explanation:

At the end point of a titration between acetic acid (HAc) and sodium hydroxide (NaOH), the acetic acid has been neutralized, forming water (H2O) and the acetate ion (Ac-).

Beyond the equivalence point, the major species present in the reaction flask would therefore be the sodium ions (Na+) as spectator ions, excess hydroxide ions (OH-) from the NaOH, and acetate ions (Ac-) from the neutralized acetic acid.

The sodium ions do not participate in the reaction and are thus considered spectator ions; they can be removed when writing the net ionic equation.

After the equivalence point, the pH of the solution is determined by the concentration of these hydroxide ions.