Question

23) B is a weak base. Which equilibrium corresponds to the equilibrium constant Ka for HB+?A) HB+ (aq) + H2O (l) ⇌ B (aq) + H3O+(aq)B) HB+ (aq) + H3O+(aq) ⇌ H2B2+ (aq) + H2O (l)C) B (aq) + H2O(l) ⇌ HB+ (aq) + OH-(aq)D) HB+ (aq) + OH-(aq) ⇌ B (aq) + H2O (l)E) B (aq) + H3O+(aq) ⇌ HB+ (aq) + H2O (l)

Answer 1

Answer:

The correct option is: A) HB⁺ (aq) + H₂O (l) ⇌ B (aq) + H₃O⁺ (aq)

Explanation:

The acid dissociation constant (Kₐ) is the equilibrium constant of a given dissociation reaction of an acid. It is also called the acidity constant as it represents the acidic strength of a given species.

The dissociation of a given acid (HA) gives the conjugate base (A⁻) and the hydrogen ion (H⁺).

HA + H₂O ⇌ A⁻ + H₃O⁺

The acid dissociation constant:

$K_{a} = \frac{\left [ A^{-} \right ]\left [ H^{+} \right ]}{\left [HA\right ]}$

Whereas, the dissociation of the conjugate base (BH⁺) of a given weak base (B), gives the base (B) and the hydrogen ion (H⁺).

BH⁺ + H₂O ⇌ B + H₃O⁺

The acid dissociation constant:

$K_{a} = \frac{\left [ B \right ]\left [ H^{+} \right ]}{\left [BH^{+} \right ]}$