Solubility of a substance

 Solubility of a substance

 

Solubility of a substance

Solubility is the ability of substance to dissolve in water.

Take a crystal of sugar add it to a glass of water. 

The sugar dissolves in water.

Here the water is called solvent and the

 substance that is sugar crystal that dissolves

 in water is called solute.

Some substances can dissolve very easily in water whereas others may not. Now we will learn by experiment the concept of soluble and insoluble substance.

(1) Take four test tubes ( A, B , C and D)

(2) Half fill each of the test tubes with water. 

(3) Add a small amount of sugar to the first test tube A.

Sand to the second test tube B

Potassium permanganate to third test tube C

and chalk powder to the fourth test tube D.

(4) Stir them well and leave it for five minutes.

 What do you observe?

Test Tube A:

The sugar dissolves in water and disappears.

The sugar is soluble in water.

Test Tube B:

Sand is a substances, which are insoluble in water

Test Tube C:

The water in the test tube in which a crystal of potassium permanganate was added turns pink. 

The crystal of potassium permanganate is soluble in water.

Test Tube D:

Chalk  is a substances, which are insoluble in water

Inferences:

There are some substances that dissolve in water and are called soluble substance, whereas others are insoluble in water and are called insoluble substance.

The substances that are soluble in water are potassium permanganate and sugar. 

(Test tube A and C)

Other substances, which are insoluble in water are sand and chalk powder. 

(Test tube B and D)