In aqueous solution, which acid–base reaction is essentially irreversible (goes to completion)?

• A. $H_{2}O$(l)+$N_{H_3}$(aq)⇌$N_{H_4}$(aq)+$O_H$(aq)
• B. $H_2{S}_{\mathrm{O}}4$(aq)+$2$NaOH(aq)→$N_2{S}_{O_4}$(aq)+$2$H2O(l)
• C. $H_{C_{\mathrm{l}}}$(aq)+$H_{2}O$(l)⇌$H_3{O}_{+}$(aq)+$C_{l_{-}}$(aq)
• D. $C_{H_3}{C}_{O_{\mathrm{O}}}H$(aq)+$H_{2}O$(l)⇌$C_{H_3}{C}_{O_{\mathrm{O}}}$(aq)+$H_3{O}_{+}$(aq)

Answer: (B)

Verified step by step guidance

1. Identify the nature of each acid-base reaction given: reversible (equilibrium) or essentially irreversible (goes to completion).
2. Recall that strong acids and strong bases react essentially completely, meaning the reaction goes to completion with negligible reverse reaction.
3. Analyze the first reaction: water (H\_2O) acting as an acid/base with ammonia (NH\_3). This is an equilibrium reaction because NH\_3 is a weak base and water is amphoteric.
4. Analyze the second reaction: sulfuric acid (H\_2SO\_4), a strong acid, reacting with sodium hydroxide (NaOH), a strong base. This neutralization reaction goes to completion, producing sulfate ions and water.
5. Analyze the third and fourth reactions: hydrochloric acid (HCl) with water, and acetic acid (CH\_3COOH) with water. HCl is a strong acid and dissociates completely, so that reaction goes to completion; acetic acid is a weak acid, so its reaction is an equilibrium.