Question

Which of the following substances has incomplete outer shell?

Answer 1

B

Explanation:

`"Al"_2"Cl"_6` consists of two `"AlCl"_3` molecules bonded together. The aluminium atoms have most of their outer shells filled by bonds with 3 chlorine atoms, and the final orbital filled by dative covalent bonds with a chlorine atom from another `"AlCl"_3` molecule.

In `"Cl"_2"O"` the oxygen atoms have two unpaired electrons, each bonds with the unpaired electron of chlorine atoms.

In `"CH"_3"Cl"•`, the chlorine atom has an unpaired electron which is becomes paired by one of carbons unpaired electrons.

In `"CH"_3^+` the carbon atom has 1 positive charge and 3 covalent bonds with 3 hydrogen atoms. However, also has thew unpaired electron electron removed to form an empty p orbital, so it has an incomplete outer shell, with only 6 of 8 electrons.