Question

What is a chemical equation? Why is it necessary to balance it ? [2 Marks]

Answer 1

Chemical equations are symbolic representations of chemical reactions that express the reactants and products in terms of their chemical formulae.
Example: Burning of coal in air, the reaction is represented as:
$C\left(s\right)+O_2\left(g\right)\to {\mathrm{CO}}_2\left(g\right)$ [1 Mark]

According to the law of conservation of mass, “matter can neither be created nor destroyed”. Thus, a chemical equation must always be balanced. [1 Mark]