

A balanced reaction is a one in which the no. of moles of each element in the reaction is equal to the no. of moles of the corresponding elements in the product.
Example,
1) 2H2 + O2 → 2H2O
2) CH4 + 2O2 → CO2 + 2H2O
3) 4Al + 3O2 → 2Al2O3
An unbalance equation is a one in which the no. of moles of each element in the reaction is not equal to the no. of moles of the corresponding elements in the product.
Examples,
1) H2 + O2 → H2O
2) CH4 + O2 → CO2 + H2O
3) Al + O2 → 2Al2O3
