Oxygen for complete combustion
This separation technique is a 4-step procedure. First, add H₂SO₄ to the solution. Because of common ion effect, BaSO₄ will not react, only Mg(OH)₂.
Mg(OH)₂ + H₂SO₄ → MgSO₄ + 2 H₂O
The aqueous solution will now contain MgSO₄ and BaSO₄. Unlike BaSO₄, MgSO₄ is soluble in water. So, you filter out the solution. You can set aside the BaSO₄ on the filter paper. To retrieve Mg(OH)₂, add NaOH.
MgSO₄ + 2 NaOH = Mg(OH)₂ + Na₂SO₄
Na₂SO₄ is soluble in water, while Mg(OH)₂ is not. Filter this solution again. The Mg(OH)₂ is retrieved in solid form on the filter paper.
<h3>Al + O2 -> Al2O3</h3>
Balance it:
<h3>2Al + 3O2 -> 2Al2O3</h3><h3 />
So you need 2 Al and 3 O2 to make 2 Al2O3 (aluminum oxide).
I'm going to assume you have all the O2 you need.
Since 2 mols of Al is needed to make 2 mols of the product, it's a 1:1 ratio. You get as much aluminum oxide for as much aluminum you burn.
So 12.5 mols if there is not a lack of the O2.
The matter of changes in volume is gas
