Get,detailed solutions to the questions of the chapter Surface Chemistry from NCERT textbooks. The objective is to helping students regarding the pattern of answering the question as per the cbse latest marking scheme.Cbse.jagranjosh.com provided you NCERT solutions for classes 12th math and science subjects.
Some questions of this chapter are given here
Q. Give reason why a finely divided substance is more effective as an adsorbent.
A finely divided substance has a large surface area. We know that adsorption is asurface phenomenon & is directly proportional to the surface area. Whether adsorption is physisorption or chemisorption, it increases with an increase in thesurface area. Thus, a finely divided substance behaves as a good adsorbent.
Q. What are the factors which influence the adsorption of a gas on a solid?
The factors which affect the rate of adsorption of a gas on a solid surface are:
a) Nature of the gas: The gases which are easily liquefiable for example- HCl,NH3 etc. are adsorbed to a great extent as compared to gases such as O2, H2
etc. This happens because Vander Waal’s forces are stronger in easilyliquefiable gases.
b) Surface area of the solid: The greater the surface area of the adsorbent, the greater is the adsorption of a gas on the solid surface.
c) Effect of pressure: Adsorption increases with an increase in pressure becauseadsorption is a reversible process and is accompanied by a decrease in pressure.
d) Effect of temperature: Adsorption is an exothermic process. Thus, according to Le-Chatelier’s principle, the adsorption decreases with an increase in temperature.