Question

Consider the following statements regarding adsorption
I. During adsorption, there is decrease in residual forces of the surface which leads toa decrease in surface energy which appears as heat.
II. The residual forces on the atoms at the surface are attractive in nature.
III. Adsorption process is spontaneous only if ($\Delta H-T\Delta S<0$).
IV. The bond formed between the adsorbate and the adsorbement during chemisorption is always covalent.

Then the correct statement(s) from the above is/are

• A. Only II and IV
• B. Only I, II and III
• C. Only I, II and IV
• D. Only IV

Answer 1

The correct option is B Only I, II and III

Particles in the bulk of the adsorbent have balanced forces whereas there are unbalanced residual forces on the particles at the surface which appears in the form of heat. So $\Delta H<0$ and , also $\Delta S<0$ as there is a decreases in the movement of gas particles