For each of the following species, analyze the placement of lone pairs (if any) around the central atom and the consequences for molecular polarity and bond strength. Provide fully reasoned answers, citing electron-pair repulsion considerations.
Species:
• PF5
• BrF4+
• XeF2
(a) For each species, write an acceptable Lewis diagram, including all formal charges.
(b) For each species, identify (i) the electron-pair geometry, (ii) the molecular geometry, and (iii) the hybridization of the central atom.
(c) Among the axial and equatorial P–F bonds in PF5, one set is expected to be longer on average. Identify which set and provide a detailed explanation based on the spatial distribution of electron pairs.
(d) Rank the three species in order of increasing molecular dipole moment, clearly justifying your ordering through symmetry and vector addition arguments.