Chemical reactions obey law of conservation of mass. So the total number of atoms of each elements in the reactants must be equal to the total number of atoms of each element in the products. So we should have to balance chemical equation.
Eg : H2 + O2 → H2O
Step -1 : Unbalanced equation = H2 + O2 → H2O
Step – 2 : Compare no. of atoms of each element on both sides.
| Atom |
No. of atoms in L.H.S |
No. of atoms in R.H.S |
| H |
2 (in H2 ) |
2 (in H2O) |
| 0 |
2 (in O2 ) |
1 (in H2O) |
No. of 0 atoms balancing – H2 + O2 → 2H2O
No. of H atoms balancing – 2H2 + O2 → 2H2O
Step – 3 : The above equation is balanced and write the coefficients in the smallest ratio. 2H2 + O2 → 2H2O
Step – 4 : Verify above equation for balancing of atoms each element on both sides. Hence the equation is balanced.
∴ 2H2 + O2 → 2H2O
