States of Matter 1 Question 87

87. Give reasons for the following in one or two sentences.

(i) Equal volumes of gases contain equal number of moles.

$(1984,1 \mathrm{M})$

(ii) A bottle of liquor ammonia should be cooled before opening the stopper.

$(1983,1 \mathrm{M})$

Show Answer

Solution:

  1. (i) $\mathrm{NH}{3}(l)$ is highly volatile, a closed bottle of $\mathrm{NH}{3}(l)$ contains large number of molecules in vapour phase maintaining high pressure inside the bottle. When the bottle is opened, there is chances of bumping of stopper. To avoid bumping, bottle should be cooled that lowers the pressure inside.

(ii) According to Avogadro’s hypothesis, “Under identical conditions of pressure and temperature, equal volume of ideal gases contain equal number of molecules.”