On what basis is a chemical equation balanced?

Hint: Balancing of chemical equations involves the addition of stoichiometric coefficients to the reactants and products. This is important because a chemical equation must obey the law of conservation of mass and the law of constant proportions.

Complete answer: Balancing the chemical equation defines the number of atoms remaining on the reactant side and the product side of the equation are always equal during the reaction. Chemical equation is a symbolic representation of a chemical reaction in which the reactants and products are denoted by their given chemical formulae.
A stoichiometric coefficient tells us about the total number of molecules of a chemical species that participate in a chemical reaction. It generally tells us about the ratio between the reactants and the products formed during the chemical reaction. The total number of atoms of an element present in a species is equal to the product of the stoichiometric coefficient and the number of atoms of the element in one molecule of the species. While balancing chemical equations stoichiometric coefficients are arranged in such a manner that it balances the total number of atoms of an element on the reactant and product side.

Note: After balancing all the individual elements compare the total number of atoms of each element on the reactant and product side. If there are no inequalities then we can say that the chemical equation is balanced otherwise it is unbalanced in nature.