What is a Balanced Chemical Equation?

 

A balanced chemical equation is a chemical equation in which the number of atoms of each element is the same on both the reactant and product sides of the equation.

This ensures the law of conservation of mass is obeyed — matter cannot be created or destroyed in a chemical reaction.

Example:

Unbalanced:

$$\text{H}_2 + \text{O}_2 \rightarrow \text{H}_2\text{O}$$

(This has 2 hydrogen atoms on both sides, but 2 oxygen atoms on the left and only 1 on the right.)

Balanced:

$$2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$$

Now it has:

• 4 hydrogen atoms on both sides 

• 2 oxygen atoms on both sides 

Why Should Chemical Equations Be Balanced?

• To Obey the Law of Conservation of Mass
  Atoms are neither created nor destroyed in a chemical reaction, so the mass of reactants must equal the mass of products.

• To Accurately Represent the Reaction
  Balancing shows the actual quantities of substances involved in the reaction.

• For Correct Stoichiometry
  It allows us to calculate the correct proportions of reactants and products (useful in lab work and industry).

• To Avoid Misinterpretation
  An unbalanced equation might give the wrong idea about how much of a substance is needed or produced.

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  BALANCING EQUATIONS