JEE Advanced2022ChemistrySurface ChemistryActual
The correct option(s) related to adsorption processes is(are)
Options
- AChemisorption results in a unimolecular layer.
- BThe enthalpy change during physisorption is in the range of 100 to 140   kJ   mol - 1 .
- CChemisorption is an endothermic process.
- DLowering the temperature favours physisorption processes.
Correct answer
A. Chemisorption results in a unimolecular layer.
Step-by-step solution
(A) First statement is correct as chemisorption results in a unimolecular layer and physisorption result in a multimolecular layer. (B) Second statement is incorrect as enthalpy change during physisorption is of the range of 20 - 40 kJmol - 1 .Gases with higher critical temperatures are readily adsorbed (C) Chemisorption is an exothermic process with 80 - 240 kJmol - 1 as the enthalpy of adsorption. (D) Lowering the temperature results in increase in the extent of physisorption.It decreases with increase of tempera