What is the reason fo the stability of colloidal sols ?
In colloidal sols, the colloidal particles carry a particular charge and the dispersion medium carries an equal but opposite charge. Due to the presence of these similar and equal charges, the particles of the colloid sol repel one another and cannot combine together to form larger particles which keep them dispersed in the medium and the colloidal remains stable.
Classify colloids where the dispersion medium is water. State their characteristics and write an example of each of these classes.
OR
Explain what is observed when
(i) An electric current is passed through a sol
(ii) A beam of light is passed through a sol
(iii) An electrolyte (say NaCl) is added to ferric hydroxide solDefine the following terms:
i)Lyophilic colloid
ii) Zeta potential
iii) Associated colloids
Write one difference in each of the following :
Homogeneous catalysis and Heterogeneous catalysis
(i) Differentiate between adsorbtion and absorption.
(ii)Out of MgCl2 and AlCl3, which one is more effective in causing coagulation of negatively charged sol and why?
(iii)Out of sulphur sol and proteins, which one form multimolecular colloids?
