Question

Select the correct statements.
(i) Physical adsorption is weak, multilayer, non-directional and non-specific.
(ii) Chemical adsorption is strong, unilayer, directional and strong.
(iii) Adsorption decreases with temperature.
(iv) Chemical adsorption is more stronger than physical adsorption.

• A. (i) and (iii) only
• B. (i), (ii) and (iv) only
• C. (iii) only
• D. All of these

Answer 1

Answer: (B)

(i), (ii) and (iv) only

1.Chemical adsorption is strong, unlayered, directional and strong.

2.Chemisorption happens due to specific forces so, it is not reversible generally.

3.Physical adsorption is weak, multilayer, non-directional and non-specific.

4. Also, physisorption happens due to weak attraction forces like van,der Waals forces. Physisorption is the process whereby molecules stick to a surface with a relatively weak interaction, up to 100 times weaker than chemisorption. Chemisorption is the adsorption by chemical bonding. Whereas physisorption can usually be reversed by adding heat, chemisorption cannot.