Question

A balanced reaction equation must have the same number of atoms of each element on both sides of the equation. The reaction given below represents the combustion of propanol. To verify that the equation is balanced, count the atoms of each element on both sides of the reaction.
2CH7OH+9O2------>6CO2+8H2O

How many C, H, O atoms is reactants?
How many C, H, O atoms in the products?

Answer 1

In order to say that a certain reaction is balanced, it should be that the number of atoms of each element in the reactants is equal to the number of atoms of the elements in the product side.

2CH7OH+9O2------>6CO2+8H2O

Reactant 
C = 2
H = 16
O = 20

Product
C = 6
H = 16
O = 20

Therefore, the reaction is not balanced since the number of carbon atoms are not equal.