Write short note on electro-dialysis.

Explanation

Electrophoresis: The movement of colloidal particles in an electric field is known as electrophoresis. The sign of the charge on the colloidal particles is found from the direction in which the particles move.

For electrophoresis, the colloidal solution is placed in a U-tube fitted with platinum electrodes. On passing an electric current, the charged colloidal particles move towards the oppositely charged electrode. For example, if arsenious sulphide sol is taken in the U-tube, its particles move towards the anode, where they get coagulated. It is due to neutralisation of the negative charge present on `As_2 S_2` colloidal particles
Cause : It is due to electrostatic forces of attraction between the colloidal particles and the oppositely charged electrode which lead to the migration of colloidal particles in an electric field.