Water is the most abundant molecule on Earth, composing 70-75% of the Earth's surface. It has many important uses including drinking, cooking, cleaning, agriculture, and generating electricity. Water is an excellent solvent, with many substances dissolving in it to form solutions. As a solvent, water plays a vital role in biological processes like respiration and photosynthesis, as well as industrial processes like manufacturing food, chemicals, metals, paper, and more. It transports nutrients, waste products, gases, and other substances throughout living things and ecosystems.

1. Water
G.Ajetrao

2. Water (H2O)
 Water is the most abundant molecule on Earth’s
surface composing 70 – 75 % of the Earth’s surface as
liquid (water) and solid state (ice) in addition to being
found as gas (water vapour) in atmosphere.

3. Uses of Water
Identify 5 uses of water.

4. Drinking

5. Cooking

6. Cleaning

7. Agriculture

8. Electricity

9. Water as Solvent
 Our daily lives are full of solutions.
 A solution is mixture in which one substance dissolves
in another.
 The part that dissolves is the solute.
 The solute dissolves in solvent.
 Example: Salt dissolves in water to form salt
solution.

10. Examples of importance of
water as solvent
1. Oxygen and carbon dioxide dissolve in water in the
blood and then carried to different parts of the body.

11. Importance of water (cont)
2. Various nitrogenous waste products of metabolism (eg.
Urea) can dissolve in water and be eliminated from the
body as urine.

12. Importance of water (cont)
3. Carbon dioxide dissolves in the cell water of leaf cells
and is then available as raw material for photosynthesis.

13. Importance of water (cont)
4. Solutions of acids in water are used by our body to
digest food.

14. Importance of water (cont)
5. Hormones produced by glands can be transported to
various organs because they are soluble in aqueous body
solutions.

15. Importance of water (cont)
6. Oceans and rivers dissolve atmospheric oxygen, which
makes it available to aquatic organisms.

16. Uses of Water in Industry
Industries that produce metals, wood, paper, chemicals,
oils etc. all use water in some part of their production
process.
Water can be used as raw material, solvent coolant,
transport agent and as energy source.

17. Water in Food Industry
 Name some food products that have water as solvent.

18. Water in Agricultural Industry

19. Water in Pharmaceutical
Industry
Pharmaceutical industries make medicines/medications.
Think of medicines in which water is used as a solvent.
Eg. Aspirin
Most drugs are taken with water as they are water
soluble.

20. Water as Solvent in
Environment
How do aquatic organisms get oxygen and carbon
dioxide?

21. Water as solvent in Paints
 Water based paints dominate and account for 80% of
paints sold in the residential market.