Help with chemical reactions

[Lgme50]

I need help figuring out what the equations are for labs we did in school. Here they are:

Reaction 1 we put Mg ribbon into a test tube with HCl, then placed a lighted wood splint at the top of the test tube. I think the equation would be

2Mg + HCl + O₂ -> MgCl₂ + H₂₀ Is this right? And is it a combustion reaction?

The next one we put ammonium carbonate into the test tube and held it over the bunsen burner; after that we put a burning wood splint near the mouth of the test tube. Would the equation be

(NH₄)₂CO₃ + O₂ -> 2NH₄ +CO₂ ?

I appreciate any help.

[peter]

In both experiments there are two independent reactions:

1. First Mg reacts with HCl:
Mg + 2HCl = MgCl₂ + H₂
Then H₂ burns in the air:
2H₂ + O₂ = 2H₂O

2. First (NH₄)₂CO₃ decomposes:
(NH₄)₂CO₃ = 2NH₃ + CO₂ + H₂O
Then hot NH₃ burns:
4NH₃ + 3O₂ = 2N₂ + 6H₂O