Question

Which one of following statements is not correct in respect of lyophilic sols ?

• A. There is a considerable interaction between the dispersed phase and dispersion medium.
• B. These are quite stable and are not easily coagulated.
• C. They carry charge.
• D. The particles are hydrated.

Answer 1

The correct option is C They carry charge.

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 colloidal state with difficulty.
When 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.