In a buffer solution consisting of acetic acid and sodium acetate, what is the conjugate base of acetic acid?

In a buffer solution made up of acetic acid and sodium acetate, the conjugate base of acetic acid is the acetate ion, represented as CH3COO-.

Acetic acid (CH3COOH) is a weak acid that can donate a proton (H+) to form its conjugate base, the acetate ion. When acetic acid dissociates, it releases a proton, resulting in the formation of acetate. This is critical in buffer solutions because the conjugate base (acetate in this case) can react with any added acid, helping to stabilize the pH of the solution.

The other options do not qualify as the conjugate base of acetic acid. The sodium ion is simply a counter ion that balances the charge of the acetate and does not participate in acid-base reactions. The hydronium ion represents an increase in acidity and is not related to the base form of acetic acid. Lastly, the hydroxide ion is associated with basic conditions, not being a product of acetic acid dissociation. Thus, the acetate ion serves the essential function of a conjugate base within this buffer system.