Question

Cataphoresis is the process used for the coagulation of colloids. It can be used for
A. Colloids having positive charge
B. Colloids having negative charge
C. Lyophilic colloids
D. All the above

Answer 1

Colloids are a mixture of very small particles of one substance that are distributed evenly throughout another substance. The substances are present as larger particles than those found in solution, but are too small to be seen with a microscope. The three forms in which all matter exist are solid, liquid, gas and colloidal solutions can be a combination of the three states

Complete step by step answer:
In chemistry a colloid is a phase separated mixture in which one substance of dispersed insoluble or soluble particles is suspended throughout another substance . The dispersed phase particles have a diameter between approximately $1 - {{ }}1000$ nanometers.
Electrophoresis is the motion of a dispersed particle relative to a fluid under the influence of a spatially uniform electric field. Electrophoresis of positively charged particles is called cataphoresis. Colloids particles sometimes carry electrical charge. The most important property of colloidal solution is that all suspended particles possess either positive or a negative charge. The repulsion between like charges repel in particles to prevent them from aggregating and settling under the action of gravity. This gives stability to sol.
Colloidal particles may acquire charges due to the presence of certain acidic or basic groups in colloidal solutions. As we know cataphoresis is the process used for the coagulation of colloids and it can be used for colloids having positive and negative charge both. Lyophilic colloids are the colloids solution in which dispersed particles have strong affinity for dispersed medium. These sols are stable and reversible.
Hence, catachresis is also used for lyophilic colloids.

So, the correct answer is Option D.

Note: Preparation of colloids; there are several methods used in the preparation of colloids such as chemical methods, electrical disintegration, peptization etc.
Purification of colloidal solution; it can be done by the process of dialysis.
There are some properties of colloids; Tyndall effect , Brownian movement , presence of charge etc. .