Question

Acetic acid is a weak acid in water because it is:

a. only slightly soluble.
b. completely dissociated into hydronium ions and acetate ions.
c. dilute.
d. unable to hold onto its hydrogen ion.
e. only slightly dissociated into ions.

Answer 1

The correct answer is e. only slightly dissociated into ions.

Step-by-step explanation:

Acetic acid (CH₃COOH) is one of the best known weak acids. It dissociates into its ions as follows:

CH₃COOH (aq) ⇄ H⁺ (aq) + CH₃COO⁻ (aq)

The dissociation constant Ka is low: aproximately 1.75 x 10⁻⁵. That indicates the equilibrium is shifted to the left and the acid is only slightly dissociated into its ions (H⁺ and CH₃COO⁻).