Question

Identify A-F in the given flow chart.

A) A: Jelly B: Shaving Cream C: Milk D: Fog E: Cheese F: Gemstones
B) A: Milk of Magnesia B: Shaving Cream C: Mud D: Cloud E: Butter F: Gemstones
C) A: Cloud B: Shaving Cream C: Jelly D: Fog E: Rubber F: Gemstones
D) A: Fog B: Shaving Cream C: Milk D: Mud E: Jelly F: Gemstones

Answer 1

Hint: Colloids are very small particles of any substance, dispersed throughout other substances. They do not settle when left undisturbed. They come under heterogeneous mixtures. Colloidal particles will have enormous surface area per unit mass due to their small size.

Complete Solution:
Before moving onto colloids, let’s first get some idea about what a mixture is. Mixture is the physical combination of two or more substances without undergoing any chemical changes. Mixtures are the blending of chemical substances such as elements and compounds.
There are two types of mixtures:
- Homogeneous mixture
- Heterogeneous mixture
Colloids are very small particles of any substance, dispersed throughout other substances. They do not settle when left undisturbed. They come under heterogeneous mixtures.
Colloids are classified based on the physical states of components: This type of classification is based on the physical state of the dispersed phase and dispersion medium. Based on whether the dispersed phase and dispersion medium is solid, liquid or gases, we can classify the colloids into eight types.

Dispersion phase	Dispersion medium	Types of colloid	Examples
Solid	Solid	Solid sol	Some colored glasses and gemstones
Solid	Liquid	Sol	Paints, cell fluids
Solid	Gas	Aerosol	Smoke, dust
Liquid	Solid	Gel	Cheese, butter
Liquid	Liquid	Emulsion	Milk, hair cream
Liquid	Gas	Aerosol	Fog, cloud
Gas	Solid	Solid sol	Foam rubber
Gas	Liquid	Foam	Froth, soap lather

-Now, let us discuss the options that are given to us.
-Fog is an aerosol. Fogs are formed in the atmosphere where the gas and liquid mix as dispersion medium and dispersed phase respectively.
-Shaving cream is a foam.
-Milk is Emulsion.
-Mud is a Sol.
-Jelly is a gel.
-Gemstones are Solid sols.

So, the correct answer is “Option D”.

Note: A gas mixed with other gas forms a homogeneous mixture; hence this system is not a colloidal system. The hydrophilic sols are more stable than hydrophobic sols because the stability of hydrophobic sols is due to charge only and hydrophilic sols are stable due to charge and solvation.