Acetic Acid (CH3CO2H) is a Weak Acid: What Happens When Dissolved in Sodium Acetate (NaCH3CO2)?

When acetic acid (CH₃CO₂H) is dissolved in sodium acetate (NaCH₃CO₂), the result is a solution that is basic.

This occurs because acetic acid is a weak acid, meaning it does not completely dissociate into ions in solution. Instead, it exists in equilibrium between its dissociated (CH₃CO₂^– and H⁺) and undissociated (CH₃CO₂H) forms.

When sodium acetate, which is the salt of acetic acid, is added to the solution, it dissociates into sodium ions (Na⁺) and acetate ions (CH₃CO₂^–). The presence of the acetate ions shifts the equilibrium of acetic acid dissociation to the left according to Le Chatelier’s principle, leading to increased production of the undissociated acetic acid, thereby decreasing the concentration of hydrogen ions (H⁺). This decrease in H⁺ concentration results in a higher pH, which indicates that the solution is basic.

In summary, a solution containing sodium acetate will act to neutralize some of the acidity of acetic acid, resulting in a basic solution.