Write the dispersed phase and dispersion medium of the following colloidal systems:
(i) Smoke (ii) Milk
What are lyophilic and lyophobic colloids? Which of these sols can be easily coagulated on the addition of small amounts of electrolytes?
Write the differences between physisorption and chemisorption with respect to the following:
(i) Specificity
(ii) Temperature dependence
(iii) Reversibility and
(iv) Enthalpy change
What is meant by coagulation of a colloidal solution? Describe briefly any three methods by which coagulation of lyophobic sols can be carried out.
Define the following terms:
(i) Brownian movement
(ii) Peptization
(iii) Multimolecular colloids
Define the following terms giving an example of each:
(i) Associated colloids
(ii) Lyophilic sol
(iii) Adsorption
Define ‘peptization’.
Peptization can be defined as a process of converting a precipitate into colloidal sol by shaking it with dispersion medium in the presence of small amount of electrolyte.The electrolyte used in this process is known as a peptizing agent.