Question

\[Fe{(OH)_3}\] sol is;
A) Macromolecular colloid
B) Multi molecular colloid
C) Micelles
D) Negative colloid

Answer 1

Hint: In colloids, one substance is divided into small particles that are known as colloidal particles and are suspended in a different medium. These colloidal particles are very small in size and insoluble. They can be separated by centrifuging or by the process of filtration.

Complete Step by Step Solution:
A colloid is a combination in which one material is suspended in another by microscopically distributed insoluble particles. The dispersed substance is sometimes referred to as the colloid. A dispersed phase and a continuous phase make up the colloid.
Colloids can be classified as
1) Based on the dispersed phase and dispersed medium:

Sr. No.	Dispersed Phase	Dispersed Medium	Type of Colloid
1	Liquid	Gas	Liquid Aerosol
2	Solid	Gas	Aerosol
3	Gas	Liquid	Foam
4	Liquid	Liquid	Emulsion
5	Solid	Liquid	Sol
6	Gas	Solid	Solid Foam
7	Liquid	Solid	Solid Emulsion
8	Solid	Solid	Solid Sol

2) Based on interaction:
a) Lyophilic: They love solvent and are thermodynamically stable. The precipitation in this type of sol is reversible. They form a lyophilic sol and are highly viscous. There is a very strong force of attraction that is present between the colloid and the liquid.
b) Lyophobic: These types of substances do not like a solvent and the thermodynamically unstable. The precipitation in them is usually non-reversible and their viscosity is almost as equal as that of the solvent.
3) Based on the size of particles in a colloid:
a) Multimolecular colloids: They are lyophilic and are formed by the aggregation of a large no of molecules/atoms. They are held together by weak Van der Waal’s forces and their molecular mass is an intermediary in nature.
b) Macromolecular colloids: They are lyophobic and are formed by large size molecules only. They have stronger Van der Waal forces in between them and have a high molecular mass as compared to multimolecular colloids. So as per the question asked above, \[Fe{(OH)_3}\] is an example of a multimolecular colloid.
Hence option B is the correct answer

Note: Methyl alcohol can be in the form of a colourless gas that acts as a precursor to numerous other organic chemical compounds and it is also being used as an aerosol propellant. It is a form of an ethanol isomer and also has several fuel applications these days.