Choose the correct net ionic equation of acetic acid being neutralized with sodium hydroxide: H+ (aq) + OH- (aq) → H2O (aq) CH3COOH (aq) + OH- (aq) → H2O (l) CH3COOH (aq) + H+ (aq) + OH- (aq) → CH3COOH (aq) + H2O (l) CH3COOH (aq) + Na+ (aq) + OH- (aq) → CH3COONa (aq) + H2O (l)
The Correct Answer and Explanation is:
The correct net ionic equation for the neutralization of acetic acid (CH₃COOH) with sodium hydroxide (NaOH) is:
CH₃COOH (aq) + OH⁻ (aq) → CH₃COO⁻ (aq) + H₂O (l)
Explanation:
In this neutralization reaction, acetic acid, which is a weak acid, reacts with sodium hydroxide, a strong base. To derive the net ionic equation, let’s break down the process step by step:
- Acetic Acid Dissociation:
Acetic acid (CH₃COOH) is a weak acid, meaning it does not dissociate completely in water. However, for the purpose of neutralization, we consider its dissociation in an aqueous solution to some extent: CH₃COOH (aq)⇌CH₃COO⁻ (aq)+H⁺ (aq)\text{CH₃COOH (aq)} \rightleftharpoons \text{CH₃COO⁻ (aq)} + \text{H⁺ (aq)}CH₃COOH (aq)⇌CH₃COO⁻ (aq)+H⁺ (aq) Here, the acetic acid molecule dissociates into acetate ions (CH₃COO⁻) and hydrogen ions (H⁺). - Sodium Hydroxide Dissociation:
Sodium hydroxide (NaOH), a strong base, dissociates completely in water: NaOH (aq)→Na⁺ (aq)+OH⁻ (aq)\text{NaOH (aq)} \rightarrow \text{Na⁺ (aq)} + \text{OH⁻ (aq)}NaOH (aq)→Na⁺ (aq)+OH⁻ (aq) The hydroxide ion (OH⁻) is responsible for neutralizing the hydrogen ion (H⁺). - Neutralization Reaction:
When the hydrogen ion (H⁺) from acetic acid reacts with the hydroxide ion (OH⁻) from sodium hydroxide, they form water (H₂O): H⁺ (aq)+OH⁻ (aq)→H₂O (l)\text{H⁺ (aq)} + \text{OH⁻ (aq)} \rightarrow \text{H₂O (l)}H⁺ (aq)+OH⁻ (aq)→H₂O (l) - Final Ionic Equation:
The sodium ion (Na⁺) does not participate in the reaction because it is a spectator ion, meaning it remains unchanged throughout the reaction. Therefore, the net ionic equation only includes the components that undergo a chemical change: CH₃COOH (aq)+OH⁻ (aq)→CH₃COO⁻ (aq)+H₂O (l)\text{CH₃COOH (aq)} + \text{OH⁻ (aq)} \rightarrow \text{CH₃COO⁻ (aq)} + \text{H₂O (l)}CH₃COOH (aq)+OH⁻ (aq)→CH₃COO⁻ (aq)+H₂O (l) This shows that acetic acid reacts with the hydroxide ion to produce acetate ions and water.
Thus, the correct net ionic equation is:CH₃COOH (aq)+OH⁻ (aq)→CH₃COO⁻ (aq)+H₂O (l)\text{CH₃COOH (aq)} + \text{OH⁻ (aq)} \rightarrow \text{CH₃COO⁻ (aq)} + \text{H₂O (l)}CH₃COOH (aq)+OH⁻ (aq)→CH₃COO⁻ (aq)+H₂O (l)
