Properties of Water

Water is an important compound. A major part of all the living organisms is made up of water.

So to study water in more detail, we need to know its physical and chemical properties.

Now let us look at the physical properties of water

Water has a molecular mass of 18.0151 $gmo{l}^{-}$.

It is a colourless and tasteless liquid.

It is a polar molecule. Hence it has dipole moment.

There is extensive hydrogen bonding present between water molecules

it is as shown above

This is why water has a higher freezing point and boiling point when compared to $H_{2}Se$ and $H_{2}S$.

Because of the of hydrogen bonding water acts as an excellent solvent

Even covalent compounds like alcohols and carbohydrates dissolve in water.

For this reason, it is able to transport ions and molecules required for plant and animal metabolism.

It has high heat of vaporization and also high heat of fusion because of hydrogen bonding

This is also responsible for the moderation of the body temperature of human beings.

Water is a good conductor of heat. That is, it has high thermal conductivity.

It also has high specific heat and heat capacity.

The chemical properties of water are as follows

Water reacts with a large number of substances.

Water has the ability to act as an acid as well as a base

That is, it has amphoteric nature.

For example, it acts a acid with ammonia and as a base with hydrogen sulphide.

Also, water can undergo self-ionisation. It is also called as auto-protolysis of water.

Water is a great source of hydrogen

The reaction is as shown

On reaction with highly electropositive metals, it releases dihydrogen by easily getting reduced

Water is oxidised to Oxygen during the process of photosynthesis

On reaction with fluorine also water gets oxidised to oxygen.

Now let us try to understand hydrolysis reactions

Water dissolves many ionic compounds because of its high hydrating tendency.

And because of the extensive hydrogen bonding, it dissolves certain covalent compounds also.

Some of the examples are as shown

From aqueous solutions, many salts can be crystallized into different hydrated salts.

Some of them are shown as above-

This association of water is basically three types:

Coordinated water

Interstitial water

Hydrogen-bonded water

Revision

Water is a colourless and tasteless liquid.

It is a polar molecule. It has high dipole moment.

Because of extensive hydrogen bonding, it has high heat of vapourisation and high heat of fusion.

It also has high freezing and boiling points. It also has high dielectric constant.

It is a good solvent. It can dissolve most of the substances.

It is responsible for the moderation of the climate and also the body temperature.

it has amphoteric nature.

It acts as an acid with a base and acts as a base with that of the acid.

Water can also undergo auto-protolysis, that is self ionisation.

It is a great source of hydrogen. It releases hydrogen when reacts with highly electropositive metals.

Water gets oxidised to oxygen during photosynthesis.

With fluorine also water gets oxidised to oxygen.

Due to its high dielectric constant, it has high hydrating tendency.

It can dissolve most of the ionic compounds and certain covalent compounds also because of this reason.

From aqueous solutions, many salts can be crystallized as hydrated salts.

Such association of water can be done by three ways: coordinated water, interstitial water and hydrogen-bonded water.

The End