## (iii) Sodium + Water → Sodium hydroxide + Hydrogen

(iii) Sodium + Water → Sodium hydroxide + Hydrogen

The skeletal chemical equation of the above reaction is

Na + H 2 O  →  NaOH + H 2

 Name of the element No. of atoms in Reactants No. of atoms in Product Sodium 1 1 Hydrogen 2 3 Oxygen 1 1

1. Number of atoms of Hydrogen in reactants number of atoms of Hydrogen in products
To balance number of Hydrogen,
We multiply the NaOH in the product by 2 (If H2 is multiplied, the total number of H in the product will be odd while that in the reactant is even. This will make balancing difficult.)
The chemical equation becomes

Na + H 2 O  →  2 NaOH + H 2

 Name of the element No. of atoms in Reactants No. of atoms in Product Sodium 1 2 Hydrogen 2 4 Oxygen 1 2

1. Now ,
Number of atoms of Sodium in reactants number of atoms of Sodium in products
To balance number of Sodium,
We multiply the Na in the Reactants by 2
The chemical equation becomes

2 Na + H 2 O  →  2 NaOH + H 2

 Name of the element No. of atoms in reactants No. of atoms in products Sodium 2 2 Hydrogen 2 4 Oxygen 1 2

1. Now,
Number of atoms of Hydrogen in reactants number of atoms of Hydrogen in products
To balance Hydrogen and Oxygen,
We multiply H 2 O in the Reactants by 2

2 Na + 2 H 2 O  →  2 NaOH + H 2

 Name of the element No. of atoms in reactants No. of atoms in products Sodium 2 2 Hydrogen 4 4 Oxygen 2 2

Now, all the elements are balanced and the balanced equation is

2 Na + 2 H 2 O  →  2 NaOH + H 2

2 Na + 2 H 2 O  →  2 NaOH + H 2

1. Class 10
2. Chapter 1 Class 10 - Chemical Reactions and Equations (Term 1)
3. Questions from inside the book

Questions from inside the book

Class 10
Chapter 1 Class 10 - Chemical Reactions and Equations (Term 1) 