Question

Anu wants to boil water quickly in a test tube. On observing the different zones of the flame, she is not able to decide which zone of the flame will be best for boiling water quickly. Help her in this activity.

Answer 1

A Flame consist of three zones:
1. The first zone is called the Outer zone:
Due to complete combustion, the outer zone is blue. This zone is the hottest in temperature when compared to the other zones. This blue coloured zone is the non-luminous part of the flame.

2. The second zone is called the Middle zone:

The yellow colour region which is the bright part of the flame is the middle zone. It is moderately hot and partial combustion of fuel takes place.

3. The third zone is called as Inner zone:

The least hot region of the flame is the inner zone. This inner zone is black due to the presence of unburnt wax vapours.

Anu should boil the water in the hottest zone of the flame, which is the non-luminous zone or the outermost zone of the flame.