Question

Which one of the following compounds is having maximum 'lone pair-lone pair' electron repulsions?

• A. ClF$_3$
• B. IF$_5$
• C. SF$_4$
• D. XeF$_2$

Hint:

Lone pair-lone pair repulsion is strongest when lone pairs are in positions where they are not spread out, such as the axial positions in square pyramidal or linear geometries.

Answer 1

The Correct Option is D

Step 1: {Understanding Lone Pair-Lone Pair Repulsions}
Lone pairs of electrons on the central atom experience repulsion from each other. The maximum repulsion occurs when the lone pairs are placed in positions that minimize their mutual interaction. The lone pair-lone pair repulsion increases with the number of lone pairs and the spatial arrangement. Step 2: {Analysis of Compounds}
In ClF$_3$, there are 3 lone pairs on the central chlorine atom and 2 bonding pairs, with a T-shaped geometry.
In IF$_5$, there are 2 lone pairs on iodine and 5 bonding pairs, with a square pyramidal geometry.
In SF$_4$, there is 1 lone pair on the sulfur atom and 4 bonding pairs, with a seesaw geometry.
In XeF$_2$, there are 3 lone pairs on the central xenon atom and 2 bonding pairs, with a linear geometry.
Since XeF$_2$ has the most lone pairs (3), the lone pair-lone pair repulsions are the highest, and hence, XeF$_2$ experiences the maximum repulsion.
Thus, the correct answer is (D).