Question

What happens when iron reacts with steam?

Answer 1

Hint: Iron \[(Fe)\] will react chemically with steam $({H_2}O)$ . This is a reaction between a metal and steam, a standard reaction which will form metal oxide and other products. Form a chemical reaction and then balance it.

Complete step-by-step answer:The question is asking for the products or result of a chemical reaction. So first let us analyze the reactants we have here. The reactants are iron and steam.
Iron is represented as \[Fe\] and steam is represented as ${H_2}O$ . Iron as we know is a metal. We know when a metal reacts with steam it forms metal oxide and hydrogen gas is evolved.
So we can try to represent the chemical reaction in the following way,
Metal $ + $ steam $ \to $ Metal oxide $ + $ Hydrogen
So now let us try to frame the above equation with the reactants we have,
$Fe + {H_2}O \to F{e_3}{O_4} + {H_2}$
Iron forms iron oxide in a third oxidation state and hydrogen gas is also formed. But this chemical reaction is not balanced. So let us try to balance this chemical reaction.
We have three iron atoms in iron oxide so we can put three iron atoms in reactant side,
$3Fe + {H_2}O \to F{e_3}{O_4} + {H_2}$
Also we see hydrogen and oxygen are not balanced. There are four oxygen atoms in iron oxide so let us add four in front of the ${H_2}O$ molecule in the reactant side.
So the equation becomes,
$3Fe + 4{H_2}O \to F{e_3}{O_4} + {H_2}$
Still hydrogen atoms are not balanced. There are eight hydrogen atoms in total in the reactant side and two on the product side. So let us add four in front of the ${H_2}$ molecule on the product side to balance hydrogen atoms. So the equation will look like,
 $3Fe + 4{H_2}O \to F{e_3}{O_4} + 4{H_2}$
Now the chemical reaction is balanced and the final equation looks like,
$3Fe(s) + 4{H_2}O(g) \to F{e_3}{O_4}(s) + 4{H_2}(g)$
So iron on reacting with steam forms iron oxide and hydrogen gas.

Note: Iron oxide and hydrogen gas are formed when steam is passed over red hot iron. But if hydrogen is passed over heated magnetic oxide then it will convert back to iron and steam. This is an example of how a reaction can be reversed.