Assertion : `PbI_(4)` doesn't exist and converts into `PbI_(2) and I_(2)` spontaneously at room temperature but `PbCl_(4)` needs heatin to convert into `PbCl_(2) and Cl_(2)`.
Reason : `Pb^(2+)` is more stable than `Pb^(4+)`due to inert pair effect.

Options

A. If assertion is true but the reason is false
B. If assertion is false but reason is true
C. If both assertion and reason are true and the reason is the correct explanation of assertion
D. If both assertion and reason are true and the reason is not the correct explanation of assertion

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understanding the Assertion
The assertion states that \( \text{PbI}_4 \) does not exist and spontaneously converts into \( \text{PbI}_2 \) and \( \text{I}_2 \) at room temperature, while \( \text{PbCl}_4 \) requires heating to convert into \( \text{PbCl}_2 \) and \( \text{Cl}_2 \).

- **Analysis**:
- \( \text{PbI}_4 \) is unstable at room temperature and decomposes into \( \text{PbI}_2 \) and iodine. This is due to the strong reducing nature of iodine, which facilitates the conversion.
- In contrast, \( \text{PbCl}_4 \) is more stable and requires heating to break down into \( \text{PbCl}_2 \) and chlorine gas.

### Step 2: Understanding the Reason
The reason states that \( \text{Pb}^{2+} \) is more stable than \( \text{Pb}^{4+} \) due to the inert pair effect.

- **Analysis**:
- The inert pair effect refers to the tendency of the s-electrons (in this case, the 6s electrons of lead) to remain non-bonding as we move down the group in the periodic table. This effect increases down the group, making the +2 oxidation state more stable than the +4 oxidation state for heavier elements like lead.

### Step 3: Conclusion
Both the assertion and the reason are true. However, the reason does not adequately explain the assertion because it does not address the differences in the reducing abilities of iodine and chlorine.

### Final Answer
- **Assertion**: True
- **Reason**: True
- **Explanation**: The reason is not the correct explanation of the assertion.