Chemistry : Surface Chemistry

What are lyophilic and lyophobic colloids? Which of these sols can be easily coagulated on the addition of small amounts of electrolytes?

Write the dispersed phase and dispersion medium of butter.

Define each of the following terms:

(i) Micelles

(ii)Peptization

(iii)Desorption

Define the following terms giving an example of each:

(i) Associated colloids

(ii) Lyophilic sol

(iii) Adsorption

Define the following terms:
(i) Brownian movement
(ii) Peptization
(iii) Multimolecular colloids

Write the differences between physisorption and chemisorption with respect to the following:

(i) Specificity

(ii) Temperature dependence

(iii) Reversibility and

(iv) Enthalpy change

Of physisorption or chemisorption, which has a higher enthalpy of adsorption? 

Define ‘peptization’.

Write the dispersed phase and dispersion medium of the following colloidal systems: 

 (i) Smoke (ii) Milk

What is meant by coagulation of a colloidal solution? Describe briefly any three methods by which coagulation of lyophobic sols can be carried out.