Question

In which of the following cases, water will have the highest and the lowest boiling point? 

i. Water is boiled in an open vessel. 

ii. Water is boiled in a pressure cooker. 

iii. Water is boiled in an evacuated vessel.

Answer 1

Higher the pressure to which a liquid is exposed, higher will be its boiling point. The pressure to which water is exposed is maximum in the pressure cooker and minimum in the evacuated vessel. Therefore, boiling point of water is highest in a pressure cooker and lowest in an evacuated vessel.