Which one of the following chargcterisitic is associated with adsorption?

Options

A. `Delta G` and `Delta S` are negative but `Delta H` is positive
B. `Delta G` is negative but `DeltaH` and `Delta` are positive
C. `Delta G, Delta H` and `DeltaS` all are negative
D. `Delta G and DeltaH` are negative but `Delta S` is positive

Answer

C

Explanation

According to Gibbs - Helmholtz equation.
`Delta G = Delta H - T Delta S`
Adsorption is spontaneous process,
so `Delta G` = negative
Adsorption is exothermic process, so `Delta H = "negative"`
In adsorption entropy decrease,
`so Delta S =` negative.
so `Delta G , Delta H ` and `Delta S` all are negative.