Answer:
The correct balanced equation is: 4Al + 3O₂ ➞ 2Al₂O₃
Explanation:
Unfortunately, that isn't the balanced equation. If you take the original equation [unbalanced],
Al + O₂ ➞ Al₂O₃
We have 1 aluminium and 2 oxygen on the left-hand side. On the right-hand side, we have 2 aluminium and 3 oxygen. So we must add 3 on the oxygen in the left-hand side and 2 on the aluminium oxide in the right-hand side.
Al + 3O₂ ➞ 2Al₂O₃
Now if you check, we have 1 aluminium and 6 oxygen on the left-hand side and 4 aluminium and 6 oxygen on the right-hand side. The number of moles of oxygen is equal but the number of moles of aluminium isn't. So we must add 4 on the aluminium of the left-hand, in order to have a balanced equation.
4Al + 3O₂ ➞ 2Al₂O₃
