Question

Al2Cl6 is more stable than AlCl3. Explain.​

Answer 1

Answer:

Al₂Cl₆ is more stable than AlCl₃ because it is a dimer.

• In case of AlCl₃, one Al atom is bonded to three Cl atoms.

• Al₂Cl₆  has two Al atoms, each bonded to four Cl atoms. This can happen because Al has vacant d-orbitals which can accommodate electrons from Cl.
• There are two interior Cl atoms, each bonded to two Al atoms and there are two exterior Cl atoms, each bonded to one Al atom.
• The bond length between an exterior Cl atom and an Al atom is 206pm and that between an interior Cl atom and Al atom is 221pm.
• The bond angle between the interior Cl-Al-Cl bond is 79° and that between exterior Cl-Al-Cl bond is 118°.
• The angle between the interior Al-Cl-Al bond is 101°.