Which of the following methods are used for the coagulation of lyophobic colloidal solutions?

I. Addition of traces of electrolyte

II. Electrophoresis

III. Mixing two oppositely charged sols

IV. Dialysis for short duration

The process of settling of colloidal particles is called coagulation.

Methods for coagulation of lyophobic

Colloidal solution are

(1) Electrophoresis –in this method, the colloidal particles move towards the oppositely charged electrode. When these cone in contact with the electrode for long these are discharged and precipitated.

(2) Mixing two oppositely charge solutions – when these are mixed in equal proportions, neutralize their charges and get precipitated.