Surface Chemist...

Which one of the following characteristics is not correct for physical adsorption

Colloidal solutions of gold prepared by different methods have different colours owing to

$$ Fe(OH)_{3} $$ when treated with $$ Fe(OH)_{3} $$ solution a reddish-brown solution is formed. The process involved is

Physical adsorption is essentially quite appreciable

Adsorption is phenomenon in which a substance

Which are not purely surface phenomena?

Which of the following metal sols cannot be prepared by Bredig's arc method?

For a given reaction, energy of activation for forward reaction $$(E_{af})$$ is $$80kJ.mol^{-1}.$$ $$\Delta H = -40kJ.mol^{-1}$$ for the reaction. A catalyst lowers $$E_{af}$$ to $$20 kJ.mol^{-1}.$$ The ratio of energy of activation for reverse reaction before and after addition of catalyst is :

Which is wrong about a positive catalyst?

Identify an emulsion from among the following.