How can I write the formula for aluminum chloride?

1 Answer
Jun 3, 2018



We know that aluminum has a valency of #+3# because it has three valence electron which it can lose easily. Similarly, chlorine has a valency of #-1# because it can gain an electron.

So in writing the formula, there is a cross of the two valencies because three chlorine atoms will have to react with one aluminium atom to gain one electron each.

#["Al"]^(3+) + 3["Cl"]^(-) -> "AlCl"_3#