Page 69 - Viva ICSE Science 5 : E-book

Water is a very good solvent. Most of the substances readily dissolve in water, that is
why it is also known as ‘the universal solvent’. Let’s gather some more information on
solubility of diff erent substances in water.

Solubility of solids in water

The most common examples of solids that dissolve in water are salt and sugar. But not
all solids dissolve in water. Solids like sand particles and chalk powder settle down at the
bottom of the container.

ACTIVITY TIME

To learn about the solubility of diff erent substances in water

You Need:
Solids like wheat fl our, turmeric powder, chalk powder and coff ee powder, water, 4–5 small
glass containers.
What to Do:

• Take the solids and dissolve each of them in water separately and see whether they are
soluble or insoluble in water.
• Note down your observations in a table and then discuss with your partner.

Solubility of liquids in water

Most of the liquids dissolve easily in water. You can observe this by performing a simple
activity. Take a mug of water and put a few drops of ink in it. You will notice that the

ink dissolves quickly and the water becomes coloured. Similarly, fruit juices and milk
are soluble in water. Some examples of liquids that are insoluble in water are petrol,

kerosene oil and butter. The liquids which dissolve completely in water are said to be
miscible in water. Similarly, the liquids which do not dissolve in water are said to be
immiscible in water.

Solubility of gases in water

Carbonated drinks are the best example to show the solubility of gases in water. In these

drinks, carbon dioxide is dissolved in water under pressure. If you shake and open a
bottle of soda (or any other aerated drink), you will see this gas coming out in the form
of bubbles. This happens because the pressure under which the gas was dissolved in

water decreases on opening the bottle and it releases out in the form of bubbles.

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