Net ionic equation for the reaction of aqueous acetic acid and aqueous potassium hydroxide.
The Correct Answer and Explanation is:
Correct Net Ionic Equation:HC2H3O2(aq)+OH−(aq)→C2H3O2−(aq)+H2O(l)\text{HC}_2\text{H}_3\text{O}_2(aq) + \text{OH}^-(aq) \rightarrow \text{C}_2\text{H}_3\text{O}_2^-(aq) + \text{H}_2\text{O}(l)HC2H3O2(aq)+OH−(aq)→C2H3O2−(aq)+H2O(l)
Explanation:
When aqueous acetic acid reacts with aqueous potassium hydroxide, a neutralization reaction takes place. Acetic acid (HC₂H₃O₂) is a weak acid, and potassium hydroxide (KOH) is a strong base.
First, understand that in a solution:
- Acetic acid partially ionizes because it is a weak acid. Most of it remains in its molecular form, HC₂H₃O₂.
- Potassium hydroxide fully dissociates into K⁺ and OH⁻ ions because it is a strong base.
The complete ionic equation is:HC2H3O2(aq)+K+(aq)+OH−(aq)→K+(aq)+C2H3O2−(aq)+H2O(l)\text{HC}_2\text{H}_3\text{O}_2(aq) + \text{K}^+(aq) + \text{OH}^-(aq) \rightarrow \text{K}^+(aq) + \text{C}_2\text{H}_3\text{O}_2^-(aq) + \text{H}_2\text{O}(l)HC2H3O2(aq)+K+(aq)+OH−(aq)→K+(aq)+C2H3O2−(aq)+H2O(l)
Notice that K⁺ appears on both sides and does not change during the reaction. Since net ionic equations include only the species that change, we remove the spectator ion (K⁺). What remains is the net ionic equation:HC2H3O2(aq)+OH−(aq)→C2H3O2−(aq)+H2O(l)\text{HC}_2\text{H}_3\text{O}_2(aq) + \text{OH}^-(aq) \rightarrow \text{C}_2\text{H}_3\text{O}_2^-(aq) + \text{H}_2\text{O}(l)HC2H3O2(aq)+OH−(aq)→C2H3O2−(aq)+H2O(l)
This equation shows the actual chemical change. The hydroxide ion (OH⁻) accepts a proton (H⁺) from the acetic acid molecule, forming water. The remaining part of the acetic acid molecule becomes the acetate ion (C₂H₃O₂⁻).
This is a classic acid-base reaction. The weak acid donates a proton, and the strong base accepts it, producing water and a conjugate base. This reaction is common in titrations involving weak acids and strong bases.
