Question

The difference between a lyophilic and lyophobic colloid is their :

• A. behaviour towards dispersion medium.
• B. filterability.
• C. scattering of light.
• D. particle size.

Answer 1

The correct option is A behaviour towards dispersion medium.

Lyophobic or solvent-hating: When the dispersed phase has less affinity for the dispersion medium, the colloids are termed as lyophobic but when the dispersion medium is water, they are given the name hydrophobic.

Substances like metals which have particles of size bigger than the colloidal particles or NaCl which has particles of size smaller than the colloidal size, fall in this category. Such substances are brought into the colloidal state with difficulty.

Lyophilic or solvent loving: When the dispersed phase has a greater affinity for the dispersion medium, the colloids are termed as lyophilic and when the dispersion medium is water, they are given the name hydrophilic. They are also called natural colloids. Substances like proteins, starch and rubber etc. are grouped under this category.