Answer:
4 moles of Fe are needed to produced 6 moles of H₂
Explanation:
This is the whole reaction:
2Fe + 3H₂SO₄ → Fe₂(SO₄)₃ + 3H₂
The equation determines:
2 mol of iron can react to 3 moles of sulfuric acid in order to produce 1 mol of iron (III) sulfate and 3 moles of hydrogen gas.
If we see the stoichiometry ratio is 2:3, from reactant to product but we need to know from product to reactant.
Then, we can solve it by an easy rule of three:
3 moles of H₂ can by produced by the reaction of 2 moles of Fe
Then 6 moles of H₂ may be produced by (6 . 2)/3 = 4 moles of Fe
4 moles of Fe are needed to produced 6 moles of H₂
