The Chemistry of Water

What is water? Water is an essential commodity for human life on this earth. In this article, some important properties of water and characteristics are described for ready reference.


Water is a very commonly available chemical compound. For the existence of humankind on the earth, water is very essential. It plays a very important role in the life of human beings. Water is a necessity for a human being, a plant, an animal and a bird. No living organism exists without water. The moment we get up in the morning till we sleep in the night we require water for our routines. No water. No life on earth. 71% of the earth is covered with water.

Water is a combination of two atoms of hydrogen and one atom of oxygen. Two atoms of hydrogen and one atom of oxygen form a molecule of water. The chemical formula of water is H2O. Two oxygen atoms are connected separately to one oxygen atom. Water exists in three physical forms. At ambient temperature water is liquid. At less than 4 degrees centigrade water gets converted into solid form(Melting point of water is zero degrees centigrade) and commonly known as ice. Generally, liquids are less dense than their solid forms. But ice density is less than water. That is why ice floats on the water. At 100 degrees centigrade water gets converted to vapour from and commonly known as steam or water vapour Boiling point of water is 100 degrees centigrade).


There are many important properties of water that make it different from other materials.

Water molecules attract each other. This property is known as Cohesion. Water molecules are attracted to each other because of their polar nature. A hydrogen atom of one water molecule will form a weak bond known as Hydrogen bond with the hydrogen atom of another water molecule. This cohesiveness gives water liquid state at normal temperature and also will give high surface tension.

Water is having another property called Adhesion. It is a measure of water's ability to attract other types of molecules. Water will be adhesive to other molecules with which it can form hydrogen bonds. Adhesion and cohesion properties of water will give capillary action to water. Because of this capillary action, only water rises up within the stems of the plants.

The specific heat and heat of vaporisation of water are very high. That is why water requires a lot of energy to break its hydrogen bonds between water molecules. Water is very commonly known as the Universal solvent. This name has come due to its ability to dissolve many different substances.

Water is the only common compound that exists in solid, liquid, and gas phase under ordinary, natural conditions.

Water can act as both an acid and a base. Water produces H+ and OH- ions on self-ionization.

Some more facts about water

Water is having other chemical names known as dihydrogen monoxide, oxidane, hydroxylic acid, and hydrogen hydroxide.

Molar mass of water: 18.01528 g/mol
Crystal structure: hexagonal

Pure water at room temperature is odourless, tasteless and nearly colourless. Water will not undergo rapid temperature fluctuations because of its high specific heat and heat of vaporisation. This property of water helps to prevent quick climatic changes on earth.

Final Words

Without water there is no life on the earth. Even though water is abundant on the earth, the majority is in seas which is not useful for the mankind. The process of purification is also very difficult. So, all of us should know the importance of water and we should conserve water for future generations.


Author: jenny16 Oct 2017 Member Level: Diamond   Points : 6

The author has listed out some of the properties of water, I would like to add some more information:

Water is an invaluable natural resource and it is impossible to imagine earth without water. Ocean water is saline and hence its not potable. Hardness of water is due to presence of dissolved salts of calcium and magnesium.

About 70% of total body weight of many living beings include water. All aquatic plants and animals live using dissolved carbon-dioxide and oxygen in water.

Water is a transparent liquid, at 100 degree Celsius water boils and freezes at minus zero degree Celsius. Pure water is non-conductor of heat and electricity.

Water exhibits a special property called 'anomalous property of expansion'. Water contracts upto 4 degree celsius and starts expanding below 4 degree celsius.

Water has a special property, it can dissolve many substances in it when compared to other solvents and hence
it 's called 'universal solvent'.

Water is a compound. Henry Cavendish proved that water is a compound of hydrogen and oxygen. Pure water is colorless but when it is in large quantities it appears to be light blue.

Some of the physical properties of water are used as standards in science. Boiled water has no taste as dissolved oxygen is removed while boiling.

The quantity of water flow is measured in units called 'Cusec'. Cusec is simplified form of cubic feet per second.

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