- What is a sol?
Sol is a colloidal suspension of a solid in a liquid.
- What is the criteria for classifying sols? What type of sols are known?
Sols are classified based on their affinity for the dispersed phase for the dispersion medium. There are types of sols – lyophobic and lyophilic.
- What is the difference between lyophilic and lyophobic sol?
A sol in which colloidal particles have an affinity for the dispersion medium is called lyophilic sol whereas, in a lyophobic sol, colloidal particles have no or very little affinity for the dispersion medium.
- What is meant by ‘dialysis’?
The phenomena of purification of sols by passing through a semipermeable membrane is known as dialysis.
- What is the special characteristic of the paper used in dialysis?
It only permits the electrolyte to pass through it and doesn’t allow the passage of colloidal particles.
- What is the nature of charge on (i) ferric hydroxide and (ii) arsenious sulphide sols?
Ferric hydroxide sol is positively charged whereas arsenious sulphide is negatively charged.