How to balance a chemical equation?
Balancing Method
Step 1: The unbalanced equation must be obtained from the chemical formulae of the reactants and the products (if it is not already provided).
Step 2: The total number of atoms of each element on the reactant side and the product side must be compared.
Step 3: Now, stoichiometric coefficients are added to molecules containing an element which has a different number of atoms in the reactant side and the product side. The coefficient must balance the number of atoms on each side. Generally, the stoichiometric coefficients are assigned to hydrogen and oxygen atoms last. Now, the number of atoms of the elements on the reactant and product side must be updated. It is important to note that the number of atoms of an element in one species must be obtained by multiplying the stoichiometric coefficient by the total number of atoms of that element present in 1 molecule of the species.
Step 3 is repeated until all the number of atoms of the reacting elements are equal on the reactant and product side.
Example:
H2+O2→H2O
The hydrogen are balanced, but the oxygens are not. We have to get both balanced. We put a two in front of the water and this balances the oxygen.
H2+O2→2H2O
However, this causes the hydrogen to become unbalanced. To fix this, we place a two in front of the hydrogen on the left side.
2H2+O2→2H2O
This balances the equation.
Balancing Method
Step 1: The unbalanced equation must be obtained from the chemical formulae of the reactants and the products (if it is not already provided).
Step 2: The total number of atoms of each element on the reactant side and the product side must be compared.
Step 3: Now, stoichiometric coefficients are added to molecules containing an element which has a different number of atoms in the reactant side and the product side. The coefficient must balance the number of atoms on each side. Generally, the stoichiometric coefficients are assigned to hydrogen and oxygen atoms last. Now, the number of atoms of the elements on the reactant and product side must be updated. It is important to note that the number of atoms of an element in one species must be obtained by multiplying the stoichiometric coefficient by the total number of atoms of that element present in 1 molecule of the species.
Step 3 is repeated until all the number of atoms of the reacting elements are equal on the reactant and product side.
Example:
H2+O2→H2O
The hydrogen are balanced, but the oxygens are not. We have to get both balanced. We put a two in front of the water and this balances the oxygen.
H2+O2→2H2O
However, this causes the hydrogen to become unbalanced. To fix this, we place a two in front of the hydrogen on the left side.
2H2+O2→2H2O
This balances the equation.
