Question

The structure of $P{F}_5$ molecule is:

• A. trigonal bipyramidal
• B. tetrahedral
• C. pentagonal bipyramidal
• D. square planar

Answer 1

Answer: (A)

${}_{15}P=1s^2,2s^{2}2p^6,3s^{2}3p^{3}3d^0$ P in excited state =
$P{F}_5=\begin{array}{ccccc}\underset{F_{{(2px)}^1}}{\underset{|}{{(s{p}^{3}d)}^1}}& \underset{F_{{(2px)}^1}}{\underset{|}{{(s{p}^{3}d)}^1}}& \underset{F_{{(2px)}^1}}{\underset{|}{{(s{p}^{3}d)}^1}}& \underset{F_{{(2px)}^1}}{\underset{|}{{(s{p}^{3}d)}^1}}& \underset{F_{{(2px)}^1}}{\underset{|}{{(s{p}^{3}d)}^1}}\end{array}$
Thus, due to $s{p}^{3}d\text{-}$ hybridization, $P{F}_5$ molecule has trigonal bipyramidal geometry.