Which one of the following is not applicable to the phenomenon of adsorption?

Options

A. `Delta H gt 0`
B. `Delta G lt 0`
C. `Delta S lt 0`
D. `Delta H lt 0`

Answer

A

Explanation

Adsorption is an exothermic process, so the `Delta H` of adsorption is always negative.
`Delta H lt 0`
`Delta G=Delta H-T Delta S`
`Delta G` = Change in Gibbs free energy
`Delta H` = Change in enthalpy
T = Temperature in Kelvin
`Delta G` = Change in entropy
Since, adsorption is a spontaneous process, the thermodynamic requirement is at constant temperature and pressure, `Delta G` must be negative. So the enthalpy `Delta H` as well as entropy `Delta S` of the system is negative.