Question

explain briefly why boron trichloride is a gas and aluminium trichloride is a dimeric solid at room temperature.

Answer 1

Because alcl3 exists as dimer al2cl6 which has bridge bond

Answer 2

Hey dear,

● Explanation -
- BF as well as AlCl3 both are electron deficient species.
- BF3 contains intramolecular pπ-pπ bonding to compensate for this electron deficiency. Thus BF3 exists as monomeric gas.
- AlCl3 shows pπ-pπ bonding with another AlCl3 molecule to compensate for this electron deficiency. Thus AlCl3 exists as dimeric gas.


Hope this helps you...