Question

Write the balanced equation for the following reaction.
Iron with steam.

Answer 1

Hint: Generally, metal reacts with steam to form metal oxide and hydrogen gas. In the case of iron, the metal oxide formed has two different iron oxides.

Complete step by step answer:
Iron reacts with steam to form iron (II, III) oxide and hydrogen gas.
The reaction is a redox reaction. The balanced chemical reaction for the reaction of iron with steam is given below:
\[3Fe + 4H{}_2O \to F{e_3}{O_4} + 4{H_2}\]
$F{e_3}{O_4}$ formed contains both iron(II) and iron(III) ions and is also written as $FeO.F{e_2}{O_3}$. $F{e_3}{O_4}$ has a cubic close packed pattern in which Fe(II) ions are located at half of the octahedral voids and Fe(III) ions are distributed uniformly between octahedral and tetrahedral sites.
The above reaction is a redox reaction. Fe is oxidised to two different oxidation states, i.e. from 0 to +2 and +3. Hydrogen is reduced from +1 to 0. The half equations of the same are:
\[2Fe \to F{e^{ + 2}} + F{e^{ + 3}} + 5{e^ - }\]
\[{H_2}O + 2{e^ - } \to {H_2} + {O^{2 - }}\]

Additional information: $F{e_3}{O_4}$ occurs in nature as mineral Magnetite. It is found in the laboratory as a black powder. It exhibits permanent magnetic properties. It is ferrimagnetic. To get Fe from the magnetite ore, it is reduced by CO in a blast furnace
\[F{e_3}{O_4} + 4CO \to 3Fe + 4C{O_2}\]
The ferrimagnetism of $F{e_3}{O_4}$ arises due to the electron spins of Fe(II) and Fe(III) ions. The coupled spins of both are anti-parallel to each other. Thus, the net effect of both is not balanced. Hence there is a permanent magnetism.

Note: Remember that $F{e_3}{O_4}$ is a compound and not a mixture. It doesn’t consist of two separate $FeO$ and $F{e_2}{O_3}$ ions but rather a single crystal structure.