JEE Advanced levelSingle correct optionDifficulty 3 of 3sc039
Consider the statements:
(i) Physisorption has an enthalpy of adsorption of about 20 to 40kJmol−1.
(ii) Chemisorption is confined to a monolayer.
(iii) Physisorption is irreversible and highly specific.
(iv) Chemisorption usually involves a high activation energy.
(v) Physisorption increases with a rise in temperature at constant pressure.
The number of correct statements is:
A2
B4
C5
D3
Answer: D
Statements (i), (ii) and (iv) are correct. Physisorption is reversible and non-specific, so (iii) is wrong, and it decreases with temperature, so (v) is wrong. Hence three statements are correct.