Writing the Chemical Equations
In a chemical reaction the reactants (one or more) react together and form a new compound, known as the product. For example, aluminium oxide reacts with dilute sulphuric acid to form aluminium sulphate and water. The reaction can be written as:
Aluminium oxide + Dilute sulphuric Acid Aluminium sulphate + water
Writing such reactions using their names requires too much space as well as labour. To simplify this the chemical equations of the reaction are written which means representing the chemical reaction with the help of symbols and formulae of the substances involved.
The chemical equation for the above chemical change will be written as:
Al2O3 + 3H2SO4 Al2(SO4)3 + 3H2O
Writing a Chemical Equation
The following steps are followed to write a chemical equation.
- Symbols and formulae of reactants are written first on the left hand side. If there is more than one reactant then a plus (+) sign is placed between the different reactants. Aluminium oxide and dilute sulphuric acid, for instance, are written as:
- An arrow is marked after the reactants to indicate that they react to form the product
- Symbols and formulae of the compounds formed (products) are written after the arrow on the right-hand side which indicates that these are formed. Here also a plus (+) sign is placed between the different compounds formed.