CHEMISTRY · Single correct · A Level · Chemistry · Bonding · Bonding
Problem
BrF3 possesses five regions of electron density, two of which are lone pairs. Which arrangement of those lone pairs gives the lowest-energy structure and why?
(a) Both lone pairs occupy axial positions, maximizing their 180∘ separation from each other.
(b) One lone pair is axial and the other is equatorial, balancing repulsions around the central atom.
(c) Both lone pairs occupy equatorial positions, minimizing the number of 90∘ lone-pair–bonding-pair interactions.
(d) Placement of lone pairs is energetically equivalent; only the number of electron domains matters in VSEPR.