Question

Translate the following statement into a chemical equation and then balance the equation:

Aluminium metal replaces iron from ferric oxide (Fe₂O₃), giving aluminium oxide and iron.

Answer 1

Balanced chemical equation: A chemical equation in which the number of atoms of each element on both sides of the equation is equal is called a balanced chemical equation.

Step 1: Representation of the chemical reaction:

• Aluminium metal replaces iron from ferric oxide (Fe₂O₃), giving aluminium oxide and iron.
• The chemical reaction can be written as:

$\underset{\mathrm{Ferric}\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3}+\underset{\mathrm{Aluminium}}{\mathrm{Al}}\to \underset{\mathrm{Iron}}{\mathrm{Fe}}+\underset{\mathrm{Aluminium}\mathrm{oxide}}{{\mathrm{Al}}_2{\mathrm{O}}_3}$

Step 2: Calculating the number of atoms on both sides of the reaction:

Elements	Number of atoms on the reactant side	Number of atoms on the product side
Fe	2	1
Al	1	2
O	3	3

Step 3: Balancing the uneven number of atoms on the reactants and products side:

1. As the number of atoms on the reactants and products side is different, so balancing of iron, aluminium and oxygen can be done by multiplying the required coefficient for them in the reaction.
2. This is done by multiplying 2 to hydrogen on the reactant side and also 2 to water on the product side, to make the two sides equal.

$\underset{\mathrm{Ferric}\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3}+\underset{\mathrm{Aluminium}}{2\mathrm{Al}}\to \underset{\mathrm{Iron}}{2\mathrm{Fe}}+\underset{\mathrm{Aluminium}\mathrm{oxide}}{{\mathrm{Al}}_2{\mathrm{O}}_3}$

Elements	Number of atoms on the reactant side	Number of atoms on the product side
Fe	2	2
Al	2	2
O	3	3

Now, we can see that the balanced equation is:

$\underset{\mathrm{Ferric}\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3}+\underset{\mathrm{Aluminium}}{2\mathrm{Al}}\to \underset{\mathrm{Iron}}{2\mathrm{Fe}}+\underset{\mathrm{Aluminium}\mathrm{oxide}}{{\mathrm{Al}}_2{\mathrm{O}}_3}$