Is BrF4 – polar or nonpolar
The correct answer and explanation is :
BrF₄⁻ (Bromine Tetrafluoride) – Polar or Nonpolar?
Answer: BrF₄⁻ is nonpolar.
Explanation:
- Lewis Structure and Electron Arrangement:
- Bromine (Br) has 7 valence electrons.
- Each fluorine (F) atom contributes 1 valence electron, and there are four fluorine atoms, adding 4 electrons.
- The negative charge (-1) adds one more electron.
- The total number of valence electrons = 7 + 4(7) + 1 = 36 electrons.
- Molecular Geometry and Hybridization:
- The bromine atom is the central atom with four bonding pairs (Br–F bonds).
- There are two lone pairs on the bromine atom.
- Using VSEPR (Valence Shell Electron Pair Repulsion) theory, the molecular shape is square planar, which is derived from the octahedral electron geometry.
- Symmetry and Dipole Moments:
- The square planar geometry (with lone pairs positioned 180° apart) makes the molecule highly symmetrical.
- Although Br–F bonds are polar due to the electronegativity difference (Fluorine = 3.98, Bromine = 2.96), the dipole moments cancel out because of the symmetric arrangement.
- As a result, the net dipole moment is zero, making BrF₄⁻ nonpolar.
- Conclusion:
Even though individual Br–F bonds are polar, the overall molecular symmetry cancels out the dipole moments, making BrF₄⁻ a nonpolar ion.