3. Chemical Reactions
All chemical reactions are represented by chemical equations. A chemical equation is a shorthand representation of a chemical reaction using the symbols and formulae of substance involved in the chemical reaction.
The symbols and formulae of the substances (elements or compounds) are arranged to show the reactants and products of a chemical reaction. Examples:
1. When potassium nitrate is heated, it gives potassium nitrite and oxygen. This reaction may be represented in the form of a chemical equation as follows.
2. Zinc and dilute sulphuric acid react to form zinc sulphate and hydrogen. This reaction is represented by a chemical equation as
Zn + H2