Chemical equations are used to represent the reactants, products, and the direction of a chemical reaction. Balancing these equations means that the number of atoms of each element on the reactant side is equal to the number of atoms on the product side. This is done to comply with the law of conservation of mass and it is called stoichiometry.
A balanced chemical equation is a chemical equation in which the number of atoms for each element in the reactants is equal to the number of atoms for that element in the products. This is done to ensure consistency with the law of conservation of mass and also allows calculation of the relative amounts of reactants and products needed to complete a reaction. Balancing chemical equations is a fundamental step in understanding the stoichiometry of a reaction and determining the amount of heat generated or absorbed.