Answer:
2, 3, 1, 3.
Explanation:
Remember that a balanced chemical equation is when we have the same number of elements for reactant and product side.
Let's see the unbalanced equation:
[tex]Fe+H_2SO_4\rightarrow Fe_2(SO_4)_3+H_2.[/tex]You can note that we have:
You can realize that we have Fe, S, and O unbalanced, but if we put '2' moles beside Fe, we will balance Fe, like this:
[tex]2Fe+H_2SO_4\operatorname{\rightarrow}Fe_2(SO_4)_3+H_2[/tex]Now, if we put '3' moles beside H2SO4 we will balance S and O, obtaining 3 moles of S, and 12 moles of O for both sides:
[tex]2Fe+3H_2SO_4\operatorname{\rightarrow}Fe_2(SO_4)_3+H_2[/tex]But H is unbalanced because on the left side we have 6 hydrogens but on the right side we have 2 hydrogens, so if we put '3' moles beside H2, we obtain the balanced chemical equation:
[tex]2Fe+3H_2SO_4\operatorname{\rightarrow}Fe_2(SO_4)_3+3H_2.[/tex]The order of the coefficients is 2, 3, 1, 3.
