Question

Why are pieces of pumice stone placed in the container before heating water while determining the boiling point of water in the laboratory ? Explain briefly.

CBSE Class IX Science SA 1 ( 2 marks)

Answer 1

Pieces of pumice stones are placed in the container before heating to avoid bumping of liquid when the temperature increases. On boiling, water releases energy as bubbles. If the bubbles do not form it can develop lot of heat and possibly explode. Addition of stones gives lots of surface area for bubbles to form and release the energy gradually.

Answer 2

Pieces of pumice stones are placed in the container before heating to avoid bumping of liquid when the temperature increases. On boiling, water releases energy as bubbles. If the bubbles do not form it can develop lot of heat and possibly explode. Addition of stones gives lots of surface area for bubbles to form and release the energy gradually.