Question

How does boiling point is increased by increasing the external pressure?

Answer 1

Well, first let us define boiling point....

Explanation:

The boiling point is the temperature at which the vapour pressure of the LIQUID is equal to the ambient pressure, and bubbles of vapour form directly in the liquid. The normal boiling point is defined when the ambient pressure (and also the vapour pressure of the boiling liquid) is ONE ATMOSPHERE.

And this is the principle behind vacuum distillation, when an otherwise involatile liquid is subject to high vacuum, and its boiling point (under these conditions of LOW pressure) is REDUCED such that boiling is accessible in the laboratory, and distillation may occur.

And in the given scenario, we have done the reverse. We have increased ambient pressure. And ACCORDINGLY, the boiling point on this liquid under `>1*atm` pressure IS INCREASED. Note that we can use this practically. Have you ever used a pressure cooker? Here the food is cooked under greater that `1*atm` pressure, and so the temperature of the boiling liquid `>100` `""^@C`. And thus GREATLY reduced cooking times can be achieved in a pressure cooker. Capisce?