This reaction can be written in the from of a word equation as:
Methane + Oxygen `to` Carbon dioxide + Water
Now, Formula of methance is `CH_(4)`
Formula of oxygen is `O_(2)`
Formula of carbon dioxide is `CO_(2)`
And, Formula of water is `H_(2)O`
Writing the formulae of all the substances in he above word equation, we get:
`" "CH_(4) + O_(2) to CO_(2) + H_(2)O`
Let us count the number of various atoms in reactans and products :
`{:(,"In reactants","In products"),("No. of C atoms:",1,1),("No . of H atoms:",4,2),("No .of O atoms",2,3):}`
The number of carbon atoms is equal on both the sides (1 each) but the number of hydrogen atoms and oxygen atoms is not equal. There are 4 hydrogen atoms on the left side but only 2 hydrogen atoms on the right side, we multiple `H_(2)O` by 2 and write `2H_(2)O.` Thus,
`" "CH_(4)+ O_(2)toCO_(2)+2H_(2)O`
Counting the number of various atoms on both the sides again, we get:
`{:(,"In reactants","In products"),("No. of C atoms:",1,1),("No . of H atoms:",4,2),("No .of O atoms",2,3):}`
Only the number of oxygen atoms is equal now. There are 2 oxygen atoms on the left side but 4 on the right side. To have 4 oxygen atoms on the left side, we multiply `O_(2)` by 2 and write `2O_(2):`
`" "CH_(4)+2O_(2)toCO_(2)+2H_(2)O`
Let us count the number of various atoms on the two sides once again:
`{:(,"In reactants","In products"),("No. of C atoms:",1,1),("No . of H atoms:",4,4),("No .of O atoms",4,4):}`
This chemical equation contains an equal number of various types of atoms in the reactants and products, so this is a balanced equation.
