What is the approximate value of the equilibrium constant, Kₙ, for the neutralization of hydrochloric acid with sodium hydroxide, shown in the equation below? HCl(aq) + NaOH(aq) → H₂O(l) + NaCl(aq)

• A. 0.1
• B. 1 × 10⁷
• C. 1 × 10⁻⁷
• D. 1

Answer: (B)

Verified step by step guidance

1. Understand that the neutralization reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) is a strong acid-strong base reaction, which typically goes to completion.
2. Recognize that for reactions that go to completion, the equilibrium constant (Kₙ) is very large, indicating that the products are heavily favored.
3. Consider the nature of the reactants and products: HCl and NaOH are strong electrolytes, dissociating completely in water, forming H₂O and NaCl, both of which are stable in aqueous solution.
4. Recall that the equilibrium constant expression for this reaction would involve the concentrations of the products over the reactants, but since the reaction goes to completion, the concentration of reactants approaches zero, making Kₙ very large.
5. Conclude that the approximate value of the equilibrium constant for this reaction is significantly greater than 1, reflecting the complete conversion of reactants to products.