Question

At given temperature, one liquid has a vapour pressure of 240 torr and another measure 420 tor. which liquid probably has the lower boiling point?
which probably has the lower heat of vaporisation ?​

Answer 1

The liquid having a vapour pressure of 420 torr will have lower boiling point and also the lower heat of vaporisation

• Vapour pressure : Vapour pressure of the liquid is defined as the pressure of the liquid at the surface of the liquid.
• When ever the vapour pressure of liquids equals the atmospheric pressure the liquid starts evaporating and is called boiling point.
• The liquid having a pressure of 420 torr is near to the atmospheric pressure and it has lower boiling point
• The heat added for the evaporation of liquid is known has heat of vaporisation
• The liquids having lower boiling point will have lower heat of vaporisation and vice versa