Question

The p K a pKa of acetic acid is 4.76 . 4.76. The p K a pKa of trichloroacetic acid is 0.7 . 0.7. Calculate the equilibrium dissociation constant, K a , Ka, of each acid.

Answer 1

Answer:

Acetic acid Ka = 1.74 × 10⁻⁵

Trichloroacetic acid Ka = 2 × 10⁻¹

Explanation:

Let's consider the acid dissociation of acetic acid.

CH₃COOH(aq) ⇄ CH₃COO⁻(aq) + H⁺(aq)

The pKa of acetic acid is 4.76. The acid dissociation constant (Ka) is:

pKa = -log Ka

- pKa = log Ka

Ka = anti log (-pKa)

Ka = anti log (-4.76)

Ka = 1.74 × 10⁻⁵

Let's consider the acid dissociation of trichloroacetic acid.

CCl₃COOH(aq) ⇄ CCl₃COO⁻(aq) + H⁺(aq)

The pKa of trichloroacetic acid is 0.7. The acid dissociation constant (Ka) is:

pKa = -log Ka

- pKa = log Ka

Ka = anti log (-pKa)

Ka = anti log (-0.7)

Ka = 2 × 10⁻¹