Get Updates
Subscribe to receive instant notifications for new study materials and important updates.
Give reason for the following observations.(a) Naphthalene... - Science
Give reason for the following observations.
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away.
Here are the reasons for the observations:
(a) Naphthalene balls disappear with time without leaving any solid:
This happens because of a process called sublimation.
Naphthalene is a substance that changes directly from a solid state to a gaseous state upon heating (or at room temperature) without passing through the liquid state.
Therefore, the balls keep forming vapors and disappear completely without leaving any residue.
(b) We can get the smell of perfume sitting several metres away:
This happens because of diffusion.
Perfume contains volatile substances that turn into vapor (gas) very quickly.
The particles of this vapor move with high speed and have large spaces between them.
They mix with the particles of air and spread out rapidly in all directions to reach us, even at a distance.