Assertion : The shape of `XeF_(4)` is square- planar.
Reason : In an octahedral geometry, a single lone pair can occupy any position but a second lone pair will occupy the opposite position to the first lone pair.

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 but reason is not the correct explanation of assertion

Explanation

To solve the question, we will analyze the assertion and the reason step by step.

### Step 1: Analyze the Assertion
The assertion states that the shape of \( \text{XeF}_4 \) is square planar.

- **Valence Electrons**: Xenon (Xe) has 8 valence electrons.
- **Bonding**: In \( \text{XeF}_4 \), xenon forms 4 covalent bonds with fluorine atoms, using 4 of its valence electrons.
- **Lone Pairs**: This leaves 4 valence electrons remaining, which can be paired up into 2 lone pairs.

### Step 2: Determine the Hybridization
The total number of electron pairs (bonding + lone pairs) around xenon is:
- 4 bond pairs (from 4 \( \text{Xe-F} \) bonds)
- 2 lone pairs

Thus, the total is \( 4 + 2 = 6 \) electron pairs. The hybridization corresponding to 6 electron pairs is \( \text{sp}^3\text{d}^2 \).

### Step 3: Determine the Geometry
The geometry of a molecule with \( \text{sp}^3\text{d}^2 \) hybridization is octahedral. However, the presence of lone pairs affects the molecular shape.

- In an octahedral arrangement, the 4 fluorine atoms will occupy the equatorial positions, forming a square plane.
- The 2 lone pairs will occupy the axial positions, one above and one below the square plane.

Thus, the molecular shape of \( \text{XeF}_4 \) is indeed square planar.

### Step 4: Analyze the Reason
The reason states that in an octahedral geometry, a single lone pair can occupy any position, but a second lone pair will occupy the opposite position to the first lone pair.

- This statement is true because lone pairs repel each other more strongly than bonding pairs. Therefore, to minimize repulsion, the second lone pair will occupy the position opposite to the first lone pair.

### Conclusion
Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, the correct answer to the question is that both the assertion and the reason are true, and the reason is the correct explanation of the assertion.

### Final Answer
Both the assertion and the reason are true, and the reason is the correct explanation of the assertion.

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