Explain how the phenomenon of adsorption finds application in each of the
(i) Production of vacuum
(ii) Heterogeneous catalysis
(iii) Froth Floatation process
(i) Production of vacuum: In Dewar flasks, activated charcoal is placed between the
walls of the flask so that any gas which enters into annular space either due to
glass imperfection or diffusion through glass is adsorbed and create a vacuum.
(ii) Heterogeneous catalysis: If the catalyst is present in a different phase than
that of the reactants, it is called a heterogeneous catalyst and this type of
catalysis is called Heterogeneous catalysis.
Example: Manufacture of from and by Haber's process using iron
Reactants are gaseous whereas catalyst is solid.
(iii) Froth Floatation process: when KCl is added to hydrated ferric oxide sol, then
a negatively charged sol is obtained with absorption of ion.