Question

how to balance a chemical reaction. explain with few examples

Answer 1

To balance a chemical equation

- You should first check the number of atoms in each reactant

- Then check the number of atoms in those substances which form the product

- Now should you try to make the number same on both of the sides. 

- Once you've made the number of particles same, You can say that your equation is balanced.

- To make the number same, you can add the number of atoms on either side. But you can't remove the existing number of particles.

- Beware, if the number is written outside the bracket like (H2SO4)2 , that means H=4, S=2 and O=8. You'll have to multiply the number inside with that of outside.

- If there's no number written, we can take it as 1. 

For e.g.- H₂+ O₂→H₂O (We see that There are 2 H and 2 O on the reactants side but 2H and only one O on the product side)
So To balance the equation, we'll have to equalize the number of O on the product side.
                   H₂+O₂→2H₂O (This gives us 2 O, but notice that the Hydrogen here gets 4 but on the reactant side there are just 2 Hydrogen atoms.)
       So again, we'll have to equalize the number of atoms on the reactant side with that of the product side
                    2H₂ + O₂→2H₂O

I hope I didn't miss out any point.
Hope this helps! :)

Answer 2

chemical equation balancing is easy.

have an example,
hydrogen + oxygen
H2 + O2 ----- H2O
this is not balanced yet

first take the reactants:
it is H and O2

now take the products :
H20
 
create a table having the information of number of atoms on both the sides. *see attachment

now try to equal the number of atoms on both sides.
so the equation now will be,
2H2+ O2  ----->2H2O
where all the atoms number are equal on both the sides.

hope it helps!!!!