Answer:
2Al + 3H2SO4 (g) → Al2(SO4)3 (aq) + 3H2 (g)
Step-by-step explanation:
On the right side we have Al2 ( so 2x aluminium, So on the left side we multiply Al by 2, On both sides is 2x Al now)
The formula for Sulfuric acid is H2SO4.
The result ( aluminium sulfate ) is Al2(SO4)3. Aluminium has an oxidation number of +3, SO4 has an oxidation number of -2 ( S(+6) + 4O (4x-2) : 6-8 = -2
So we have to multipy aluminium 2x and SO4 (3x) to equal.
On the right side we have 3x S, so on the right side we have to multiply H2SO4 also by 3 to get the same amount.
This results in 12x Oxygen (3xO4). Which is the same as the right side.
On the left side we have 6H ( 3xH2) so on the right side we multiply H2 by 3 to get the same amount.
So we have on both sides:
2x Al
6xH
3xS
12xO