객관식
Pure water can ionize into which of the following?
94
views
17. Acid and Base Equilibrium
Auto-Ionization
객관식
Which of the following correctly completes the autoionization reaction of water and provides the expressions for its equilibrium constant (K_c) and ion product (K_w)?
A
H_2O(l)
ightleftharpoons H_2(g) + O_2(g); K_c = \(\frac{[H_2][O_2]}{[H_2O]}\); K_w = [H_2][O_2]
B
2 H_2O(l)
ightleftharpoons H_3O^+(aq) + OH^-(aq); K_c = \(\frac{[H_3O^+][OH^-]}{[H_2O]^2}\); K_w = [H_3O^+][OH^-]
C
2 H_2O(l)
ightarrow H_2O_2(aq) + H_2(g); K_c = \(\frac{[H_2O_2][H_2]}{[H_2O]^2}\); K_w = [H_2O_2][H_2]
D
H_2O(l)
ightleftharpoons H^+(aq) + OH^-(aq); K_c = \(\frac{[H^+][OH^-]}{[H_2O]}\); K_w = [H^+][OH^-]
검증된 단계별 안내1
Identify the correct autoionization reaction of water. The autoionization involves water molecules reacting with each other to form hydronium ions (H_3O^+) and hydroxide ions (OH^-), not gases like H_2 or O_2.
Write the balanced chemical equation for the autoionization of water: \(2\ H_2O(l) \rightleftharpoons H_3O^+(aq) + OH^-(aq)\).
Express the equilibrium constant \(K_c\) for this reaction using the concentrations of the aqueous species and water: \(K_c = \frac{[H_3O^+][OH^-]}{[H_2O]^2}\).
Understand that the ion product constant of water, \(K_w\), is defined as the product of the concentrations of the hydronium and hydroxide ions at equilibrium: \(K_w = [H_3O^+][OH^-]\).
Note that because water is a pure liquid, its concentration is often treated as constant and incorporated into the equilibrium constant expression, simplifying \(K_c\) to \(K_w\) in many contexts.
관련 영상
관련 실천
