Question

According to VSEPR theory, a molecule with the general formula AX5E (A is the central atom, X is the bonded atom and E is a lone pair of electrons) has how many regions of electron density around the central atom? AX5E will have what kind of electronic geometry? AX5E will have what kind of molecular geometry?

a) 5 regions; trigonal bipyramidal; square pyramidal
b) 5 regions; trigonal bipyramidal; seesaw
c) 6 regions; octahedral; square planar
d) 6 regions; octahedral; octahedral

Answer 1

A molecule with the formula AX5E has 6 electron density regions, an octahedral electronic geometry, and a square pyramidal molecular geometry.

Step-by-step explanation:

According to VSEPR theory, a molecule with the general formula AX5E has 6 regions of electron density around the central atom due to the presence of five bonding pairs (BP) and one lone pair (LP). The electronic geometry for AX5E is therefore octahedral. However, with the lone pair occupying one of those positions, the molecular geometry becomes square pyramidal. The lone pair prefers to occupy an equatorial position in a trigonal bipyramidal geometry to minimize repulsions, but since octahedral geometry provides equivalent positions for the lone pair, the molecular geometry adapts to square pyramidal when the lone pair is included.