Can someone please explain how to do this for me? I will give a medal. Write the complete balanced equation for the reaction between aluminum metal (Al) and chlorine gas (Cl2)

Question

anonymous · Answer

So, we need to balance the no.of atoms on both sides:

Al : Atomic no = 13 (2, 8, 3)
Cl:  Atomic no = 17 (2, 8, 7)

1. Because Cl has only 7 electrons in its shell it shares 2 of its electrons with another CL atom to gain 8  electrons in its outer shell and become Cl2, so its stable for now. 
2. but if we break this molecule then Cl has it has 7 electrons in its outer shell.
3. So now we have $$Al ^{3+} $$ and $$Cl ^{-}$$ 
4. In order to balance this we need 3 Cls so you have $$AlCl _{3}$$
5. But remember we began with 2 Clorine atoms, so we need to double this figure to get
$$2AlCl _{3}$$

Therefore, the balanced equation is:
$$2Al + 3Cl _{2} --> 2AlCl _{3}$$