Assertion (A) : `PbI_4` is a stable compound .
Reason (R) : Iodide ion stablised by higher oxidation state

Options

A. (a) If both (A) and (R) are correct and (R) is correct explanation of (A)
B. If both (A) and (R) are correct and (R) is not correct explanation of (A)
C. (c) If (A) is correct , but (R) is incorrect
D. (d) If both (A) and (R) are incorrect

Explanation

To analyze the assertion and reason provided in the question, we will break it down step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that `PbI4` (lead(IV) iodide) is a stable compound.
- To evaluate this, we need to consider the oxidation states of lead in this compound.

2. **Determining the Oxidation State of Lead**:
- In `PbI4`, lead (Pb) has an oxidation state of +4.
- Iodine (I) has an oxidation state of -1. Since there are four iodide ions, the total contribution from iodine is -4. Thus, for the compound to be neutral, lead must be +4.

3. **Comparing Oxidation States**:
- Lead can exhibit two common oxidation states: +2 and +4.
- Generally, the +2 oxidation state of lead is more stable than the +4 oxidation state due to the inert pair effect.

4. **Inert Pair Effect**:
- The inert pair effect refers to the tendency of the s-electrons (in this case, the 6s electrons of lead) to remain non-bonding or "inert" when forming compounds, especially in heavier elements.
- This effect makes the +2 oxidation state more stable than the +4 oxidation state for lead.

5. **Conclusion on Assertion**:
- Since the +4 oxidation state is less stable, `PbI4` is not a stable compound. Therefore, the assertion that `PbI4` is stable is incorrect.

6. **Understanding the Reason**:
- The reason states that the iodide ion is stabilized by the higher oxidation state.
- However, this is not true for larger halides like iodine. Higher oxidation states are generally stabilized in smaller and more electronegative halogens (like fluorine) but not in iodine.

7. **Conclusion on Reason**:
- Since the reason is also incorrect, we conclude that both the assertion and the reason are false.

8. **Final Answer**:
- Both the assertion and the reason are incorrect.