If `pK_b gt pK_a` then the solution of the salt of weak acid and weak base will be -

Options

A. Neutral
B. Acidic
C. Basic
D. Amphoteric

Answer

To solve the question "If \( pK_b > pK_a \), then the solution of the salt of weak acid and weak base will be -", we can follow these steps:

### Step 1: Understand the relationship between \( pK_a \) and \( pK_b \)
- \( pK_a \) is a measure of the strength of an acid; lower values indicate stronger acids.
- \( pK_b \) is a measure of the strength of a base; lower values indicate stronger bases.
- If \( pK_b > pK_a \), it implies that the weak acid is stronger than the weak base.

### Step 2: Identify the nature of the salt formed
- The salt formed from a weak acid and a weak base can be represented as \( \text{Salt} = \text{Weak Acid} + \text{Weak Base} \).
- For example, if we consider acetic acid (\( CH_3COOH \)) as the weak acid and ammonium hydroxide (\( NH_4OH \)) as the weak base, the salt formed would be ammonium acetate (\( CH_3COONH_4 \)).

### Step 3: Analyze the dissociation of the salt in water
- When the salt \( CH_3COONH_4 \) is dissolved in water, it dissociates into \( CH_3COO^- \) and \( NH_4^+ \).
- The \( NH_4^+ \) ion can donate a proton to water, forming \( NH_3 \) and \( H_3O^+ \), making the solution acidic.
- The \( CH_3COO^- \) ion has a weaker tendency to accept protons compared to the \( NH_4^+ \) ion's tendency to donate protons.

### Step 4: Determine the overall nature of the solution
- Since \( pK_b > pK_a \), the weak acid (acetic acid) is stronger than the weak base (ammonium hydroxide). This means that the solution will have a higher concentration of \( H_3O^+ \) ions than \( OH^- \) ions.
- Therefore, the solution will be acidic.

### Conclusion
The solution of the salt of a weak acid and a weak base, when \( pK_b > pK_a \), will be **acidic**.

---