Question

In hydrolysis of a salt of weak acid and strong base, A\(^-\) + H\(_2\)O \(\rightleftharpoons\) HA + OH\(^-\), the hydrolysis constant (\(K_h\)) is equal to

• A. \(K_w/K_a\)
• B. \(K_w/K_b\)
• C. \(K_a/C\)
• D. \(K_w \times K_a/K_b\)

Hint:

For weak base-strong acid salt, \(K_h = K_w/K_b\).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
\(K_h = [\mathrm{HA}][\mathrm{OH}^-]/[\mathrm{A}^-]\).
Step 2: Detailed Explanation:
\(K_a = [\mathrm{H}^+][\mathrm{A}^-]/[\mathrm{HA}]\), \(K_w = [\mathrm{H}^+][\mathrm{OH}^-]\)
\(K_w/K_a = [\mathrm{OH}^-][\mathrm{HA}]/[\mathrm{A}^-] = K_h\)
Step 3: Final Answer:
\(K_h = K_w/K_a\).