The main effects of pressure on the boiling point of liquids are: –
All liquids expand when they vaporize. The effect of pressure on the surface the expansion and delay vaporization. Thus, the boiling point is raised on the application of pressure.
Application: The pressure Cooker.
This was invented by Denys Papin, a Frenchman , in 1681. By means of a valve arrangement, the steam formed is not allowed to escape freely. The pressure over the water surface consequently builds up, resulting in the boiling point of water being raised to about 1200 C. The food cooks faster due to the rise in temperature.