Month: May 2020

May 29

Types Of Mixtures (for distillation)

Miscible liquid mixtures are of three types which can be revealed by plotting the vapor pressure against mole fraction of component.

1. First type of mixture:

The Vapor pressure curve exhibit minimum area. If we take mixture which has excess of ‘x’ (more volatile compound), we are somewhere at ‘C’ on the curve. On distillation, vapor will contain excess of ‘x’ and thus the remaining mixture will get richer in ‘y’. Finally we reach the point ‘D’ where vapor pressure is minimum and thus the boiling point is maximum. Here the mixture will distill unchanged in composition. Read more

May 27

Distillation Principle and Types

Distillation: it is a separation process which is used to separate desired component from a liquid mixture by making use of differences in volatilities of different components of the mixture.

Working principle of distillation: heating a mixture at a specific temperature, i.e. boiling point of liquid, is vaporization takes place. The hot vapor is collected and condensate to separate the components of substances. Highly volatile substances are separated from less volatile compounds in distillation.

Principle of distillation:

  1. Condensation of vapor without allowing any liquid to return to the still i.e. without refluxing.
  2. Return of the part of condensate to the still under such condition that this returning liquid is brought into intimate contact with vapors on their way to their condenser. This method is also called distillation with reflux or rectification or fractional distillation.

Read more