XeF3+ contains polar covalent bonds. Determine whether the following statement is true or false: XeF3+ has a permanent dipole moment. And please write down your explanation.
The Correct Answer and Explanation is:
Correct Answer: True
Explanation
The molecule XeF₃⁺ (xenon trifluoride cation) indeed contains polar covalent bonds and has a permanent dipole moment. Here’s why:
First, consider the structure of XeF₃⁺. The central atom, xenon (Xe), is a noble gas capable of expanding its octet due to the availability of d-orbitals. In XeF₃⁺, xenon forms three bonds with fluorine atoms. Fluorine is highly electronegative, pulling electron density toward itself in each Xe–F bond, making each bond polar covalent.
To understand whether the molecule has a permanent dipole moment, we must examine its molecular geometry. XeF₃⁺ has five electron domains: three bonding pairs (with fluorines) and two lone pairs on the xenon atom. According to Valence Shell Electron Pair Repulsion (VSEPR) theory, this results in a trigonal bipyramidal electron geometry, but the two lone pairs occupy equatorial positions to minimize repulsion. The actual molecular shape is therefore T-shaped.
This T-shaped geometry is asymmetrical, meaning that the individual bond dipoles do not cancel each other out. Instead, the polar Xe–F bonds create a net dipole pointing in a specific direction. Thus, XeF₃⁺ has a permanent dipole moment.
If the molecule were symmetric, like CO₂ (linear) or BF₃ (trigonal planar), the bond dipoles could cancel out, resulting in no net dipole moment. But in the case of XeF₃⁺, the asymmetry introduced by the lone pairs and the T-shaped geometry prevents this cancellation.
Therefore, the presence of polar bonds and a non-symmetric geometry together mean that XeF₃⁺ is a polar molecule with a permanent dipole moment.
Conclusion: The statement is true — XeF₃⁺ has a permanent dipole moment due to its polar bonds and asymmetric molecular shape.
