Page 100 - Science Class 6 Times Publication

Activity 9.7

To show the process of sublimation
Materials required: An evaporating basin, camphor, funnel, a test
tube, cotton, etc.
Procedure

1. Take some pieces of camphor in an evaporating basin.

2. Cover it with an inverted funnel.
3. Put a test tube over the stem of funnel.
4. Put wet cotton around the test tube.

5. Heat the basin with gas burner or spirit lamp.
Cotton
Camphor Test tube
Funnel
Evaporating basin

Tripod Stand Burner

The process of sublimation

Observation: You can see the changing of solid camphor into vapour.
The vapour camphor converts into solid due to cooling by wet cotton.
The solid camphor gets deposited in the inner walls of test tube.

Conclusion: The camphor shows the process of sublimation.

Uses of change in state of matter

Change in the state of matter due to heating and cooling has many

uses in practical life. Some of the uses are as follows:

1. Rain occurs due to change in state of matter. Water of ocean or
river vapourizes due to the heat of the sun. The water vapour
mixes with other gases and cloud is formed. When cloud reaches
the cold place, the water vapour condenses to the water. Thus,
rainfall occurs.

2. The clothes after washing are kept in the sun for making it dry.

Times' Crucial Science and Environment 96 Book 6