Question

give reason for naphthalene balls disappear with time without leaving solid
we can get smell of perfume sitting several meters away

Answer 1

Answer: Naphthalene balls disppear without leaving any solid because it undergo through sublimation process and gets converted into vapour form which later get rapidly mixed with the air and cause smell.

Answer 2

Correct question:-

(a)Naphthalene balls disappear with time without leaving any solid.

(b) We can get the smell of perfume while sitting several metres away.

$\huge\star{\orange{\underline{\underline{\mathbb{EXPLANATION:}}}}}$

______________________________

• At room temperature, naphthalene balls undergo sublimation where in they directly get converted from a solid to a gaseous state without having to undergo the intermediate state, i.e., the liquid state.

• Molecules of air move at a higher speed and have large intermolecular spaces.

• Perfumes comprise of flavoured substances that are volatile which scatters quickly in air, becoming less concentrated over a distance.

• Hence we are able to smell perfume sitting several metres away.