Which one of the following characteristics is associated with adsorption?
- G and H are negative but S is positive.
- G and S are negative but H is positive.
- G is negative but H and S are positive.
- G, H and S all are negative.
Answer
(4) G, H and S all are negative.
Solution
As per NCERT, adsorption is a spontaneous process, so G is negative.
When gas molecules are adsorbed, their freedom of movement is restricted S is negative.
For G = H - T S to be negative with S negative, H must be negative (adsorption is exothermic).
Answer: (4)