Give reasons for the following in one or two sentences.
(`a`) A bottle of liquor ammonia should be cooled before open it the stopper.
(`b`) Equal volumes of gases contain equal number of moles.

Explanation

Liquid ammona bottle contains the gas under very high pressure. If the bottle is opened as such, then the sudden decrease in pressure will lead to a large increase in the volume of the gas. As a result, the gas will come out of the bottle all of a sudden with force. This will lead to the breakage of the bottle and alos ome serious accident. However. If the bottle is cooled under tap water for sometime, this will lead to a decrease in the volume of the gas to a large extent. If the seal is opened now, the will come out of the bottle at a slow rate, thus, reducing the chances of accident.