Question:
When BCl3 is treated with water, it hydrolyses and forms [B[OH]4]- only whereas AlCl3 in acidified aqueous solution forms [Al (H2O)6]3+ ion. Explain what is the hybridisation of boron and aluminium in these species?
Solution:
AlCl3 + 6H2O → [Al(H2O)6]3+ + 3Cl–
The 6 H2O molecules get attach with Al i.e. donate 6 electron pair to the 3s,3p and 3d orbital of Al3+ ion.
Thus, the hybridization of the Al atom in [Al(H2O)6]3+ species is sp3d2.