Identify a molecule with incomplete octet from following.
Identify a molecule with incomplete octet from following.
$\mathrm{SF}_6$
$\mathrm{PCl}_5$
$\mathrm{LiCl}$
$\mathrm{H}_2 \mathrm{SO}_4$
Solution
$\mathrm{Li}$ in $\mathrm{LiCl}$ has less than eight electrons in its valence shell. It has only four electrons. Hence, it has an incomplete octet. Molecules like $\mathrm{SF}_6$, $\mathrm{PCl}_5, \mathrm{H}_2 \mathrm{SO}_4$ have an expanded octet. They have more than eight electrons around the central atom.