Page 80 - Active Science 5 Ebook and Activity

1. Evaporation: The process of converting a liquid to vapour is called evaporation.
Water containing soluble impurities like salt or sugar is heated. On heating, water

changes into water vapour and escapes. The impurities (salt or sugar) are left behind.

Activity 6.7

Aim : To demonstrate the process of evaporation.
Materials Required: Salt, warm water and a bowl.

Procedure : • Take a bowl and put some warm water in it.
• Then add 2 tablespoons of salt in it.
• Shake it properly.

• Leave the bowl in an open place for an hour.
• Observe the bowl and note what happened.

Observation : You will notice that water escaped and the salt residue remains in
the bowl.
Conclusion : Water has evaporated and the salt dissolved in water has remained
in the bowl.

: This exactly happens when salt evaporates from seawater and get
piled up on the shore.

After an hour

Salt

2. Distillation: It is the process of purifying water by boiling it and condensing its
vapour. Distillation can be done on a small scale in a glass vessel known as distillation

flask.

Activity 6.8

Aim : To demonstrate the process of distillation.
Materials Required: Impure water (mix mud in water), distilling flask with thermometer,

condenser with stand, beaker, rubber cork, Bunsen burner, tripod
stand, stand with clamp, basin filled with sand
Procedure : • Take a distilling flask and pour the salty water into it.

80 Active Science-5