Short Answer TypeWrite three distinct features of chemisorptions which are not found in physisorptions.
Write the main reason for the stability of colloidal sols.
There are two main reasons for the stability of colloidal sols:
Solvation: Colloidal particles are covered by a sheath of liquid in which they are extensively solvated, thereby providing stability.
Electrostatic stabilisation: Presence of equal and similar charges on the colloidal particles prevents coagulation of the colloidal sol.
(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?
Define the following terms:
i)Lyophilic colloid
ii) Zeta potential
iii) Associated colloids
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 solWrite one difference in each of the following :
Homogeneous catalysis and Heterogeneous catalysis
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