Question

Consider the following four xenon compounds: XeF₂, XeF₄, XeF₆ and XeO₃. The pair of xenon compounds expected to have non-zero dipole moment is 
 

• A. XeF₄ and XeF₆
• B. XeF₂ and XeF₄
• C. XeF₂ and XeO₃
• D. XeF₆ and XeO₃

Hint:

Dipole moments are non-zero when molecules have an asymmetric shape with uneven electron distribution.

Answer 1

The Correct Option is D

To determine which xenon compounds have a non-zero dipole moment, we need to analyze their molecular geometry. A compound has a non-zero dipole moment if it has an asymmetrical electron distribution. Let's evaluate the molecular geometry for each xenon compound:

1. XeF₂ (Xenon Difluoride): XeF₂ has a linear geometry. It consists of two fluorine atoms bonded to xenon with bond angles of 180°. This symmetrical shape results in the dipole moments canceling each other out, making the overall dipole moment zero.
2. XeF₄ (Xenon Tetrafluoride): XeF₄ has a square planar geometry. This is due to the presence of two lone pairs on xenon. The symmetrical arrangement means the dipole moments cancel each other, resulting in a net dipole moment of zero.
3. XeF₆ (Xenon Hexafluoride): XeF₆ has a distorted octahedral geometry, which usually gives it some asymmetry. This asymmetry leads to a non-zero dipole moment, as the dipole moments do not completely cancel out.
4. XeO₃ (Xenon Trioxide): XeO₃ has a trigonal pyramidal geometry due to the presence of a lone pair, causing an asymmetrical distribution of electron density. This results in a non-zero dipole moment.

Based on these analyses, the compounds with non-zero dipole moments are XeF₆ and XeO₃. Therefore, the correct answer is:

XeF₆ and XeO₃