Question

Give a 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 meters away. [3 MARKS]

Answer 1

Reasoning out: 1.5 Marks each

a. Naphthalene ball is a sublimate and a sublimate turns into vapour without changing into liquid. Thus, naphthalene balls disappear with time without leaving any solid.

b. Perfume turns into gas at room temperature. The vapour of perfume travels up to several meters because of diffusion. That’s why we can get the smell of perfume even when sitting several meters away.