Question

Which of the following is not the correct difference between lyophobic and lyophilic sols?

• A. (Lyophobic sols) Require special methods for preparation (Lyophilic sols) Can be prepared by shaking with the solvent
• B. (Lyophobic sols)Are reversible (Lyophilic sols) Are irreversible
• C. (Lyophobic sols) Easily coagulated by electrolytes (Lyophilic sols)Cannot be easily coagulated
• D. (Lyophobic sols) Are less stable (Lyophilic sols) Are more stable

Answer 1

The correct option is B (Lyophobic sols)Are reversible (Lyophilic sols) Are irreversible

• The word ‘lyophilic’ means liquid-loving.
  
• The word ‘lyophobic’ means liquid-hating.
  
• In Lyophilic sols if the dispersion medium is separated from the dispersed phase, the sol can be reconstituted by simply remixing with the dispersion medium. That is why these sols are also called reversible sols.
  
• In Lyophobic sols when dispersed phase simply mixed with the dispersion medium do not form the colloidal sol. hence, they are called irreversible sols. Lyophilic sols are quite stable and cannot be easily coagulated.
• Lyophobic sols are readily coagulated on the addition of small amounts of electrolytes, by heating or by shaking and hence, are not stable.