Question

Which is not lyophilic colloid?
A. Milk
B. Gum
C. Fog
D. Blood

Answer 1

To answer this question we should know what lyophilic colloid is. Lyophilic is the type of colloidal based on the interaction between dispersed (solute) and dispersion phase (solvent). In lyophilic colloids, the dispersed phase has good interaction with the dispersion phase.

Complete answer:
The phase which remains dispersed (solute) is known as the dispersed phase. The phase in which the dispersed phase solubilize that is solvent is known as the dispersion phase.
Based on the interactions of the dispersed phase and dispersion phase, the colloids are divided into two parts:
Lyophilic: Lyophilic colloids are liquid loving means dispersed phase easily interacts with the dispersion phase, so they can easily form by mixing. Lyophilic colloids are reversible colloids. Lyophilic colloids are stable. They do not coagulate, so do not require a stabilizer. The lyophilic colloid can be separated by just evaporation and can again form by remixing, so they are reversible.
Milk is the colloid in which solid oil globules remain suspended in a water-based liquid system. We can separate the components of the milk, so milk is a lyophilic colloid.
Gum is the colloid in which the dispersed phase is solid gum and the dispersion phase is liquid water. The gum can be separated from the water and can be remixed, so the gum is a lyophilic colloid.
Fog is colloid in which the dispersed phase is liquid water droplet and the dispersion phase is gas. We cannot separate the water droplet from gas and cannot be remixed, so fog is not a lyophilic colloid.
Blood is colloidal and has solid cells suspended in liquid blood plasma. In hospitals, the cells are separated from the plasma and they can be remixed, so blood is a lyophilic colloid.
So, fog is not lyophilic colloid.
Therefore, option (C) is correct.
Note: Lyophobic: In lyophobic colloids, the dispersed phase does not interact with the dispersion phase easily. We have to make them by using specific methods. Metal sulphides are the lyophobic colloids that are made by a specific method such as gold sol which is prepared by Bredig’s arc method. Lyophobic colloids are liquid haters so, the dispersed phase does not interact easily with the dispersion phase, so they can be prepared by special methods only. Lyophobic colloids are irreversible colloids. Lyophobes require stabilizers because they coagulate easily.