Question

Explain the following.
(a) Liquid ammonia bottle is cooled before opening the seal.
(b) The type of an automobile is inflated to a slightly lower pressure in summer than in winter.

Answer 1

(a) Cooling or decreasing the temperature decreases the vapor pressure, thereby preventing liquid ammonia to evaporate. Liquid ammonia has a very low vapor pressure which makes it evaporate. Hence, to prevent this from happening, liquid ammonia is cooled beforehand.

(b)Temperature is directly proportional to pressure. In summer, Temperature increases, the pressure inside the tire also increases and thus to prevent the bursting of the tire, it is inflated to a slightly lesser pressure in summer as the temperature is high.