Balancing A Chemical Equation
Balancing of chemical equation means making the number of atoms of each elements equal on both sides of the equation.
Generally there are four methods of balancing the equation :-
- Hit and Trial methods / Trial and error method
- Partial Equation method
- (Oxidation number method)[https://www.texoviva.com/balancing-of-chemical-equations-of-redox-reaction-using-oxidation-number/]
- Ion-electron method But we will discuss only first two methods here. Rest two will be discussed in later.
1. Hit and Trial / Trial and error method
This is the most simplest method. This can be used for simple equation, complex equation can be balanced by the other methods. There is no definite rule as such but I will try to break it into two steps if possible.
Write down the correct equation. This is also called skeleton equation. Example -
Select the biggest fromula from the equation for example in above example and try to equlize the number of atoms on the both sides. Then similarly approad the other equations.
Partial Equation Method
Hit and trial method can be used only for simple methods. Some complex equations require different approach to balance the equation.
The chemical reaction represented by the equation is supposed to proceed in two or more steps.
Reaction equation for each step should be written down and then balance by the hit and trial method. These are known as partial equations.
If necessary, the partial equation are multiplied by suitable integers so as to cancel those intermediate products which do not occur in the final equation.
Finally, the partial equation are added up to get the final balanced equation.
Equations Balanced using Hit and Trial :-
Example 1 Balance
The biggest formula in the equation is
To equilise the number of atoms of Fe and O on both sides, multiply Fe by 3 and by 4. We have
The equation has 8 atoms of H on R.H.S. as against 1 on L.H.S. To equalize, multiply H atoms by 8 and convert it into molecular state.
We got balanced molecular formula.
Equation balanced using Partial Method :-
Example 1 Balance
Chlorine reacts with water
Sodium Hydroxide neutralises the acids formed in step 1
Sodium Hupochlorite, NaClO, is unstable at higher temprature. It undergoes self oxidation reduction to give a mixture of sodium chloride and sodium chlorate.
To cancel products with don’t occur in final equation multiply them by 3 and add all the four equations.
This represents the balanced chemical equation.