Question

What is a balanced chemical equation? Why should a chemical equation be balanced?

Answer 1

Chemical Equation: A balanced chemical equation is the symbolic representation of a chemical reaction in which the reactants and products are represented in their symbols with their number of moles involved for complete reaction.

A chemical equation is balanced to follow the law of conservation of mass. 

Answer 2

A balanced equation is the one in which number of different atoms on both the reactant and product sides are equal. Balancing chemical equation is necessary for the reaction should obey The Law of Conservation of energy. Balancing the chemical equation has no defined method and is purely a trial and error attempt.