Which one of the following characteristics is associated with adsorption?
G is negative but
H and
S are positive
G,
H and
S all are negative
G and
H are negative but
S is positive
G and
S are negative but
H is positive
As learnt in
Change in Q during adsorption -
Q=
H - T
S
- wherein
Q can be negative if
H is sufficiently high negative value as -T
S is positive. In an adsorption process which is spontaneous, a combination of these two factors make
G negative.
Absorption is a spontaneous process. So in the equation,
will be negative.
will be negative because it is an exothermic reaction.
will be negative because randomness of the universe decreases in the process.
Option 1)
G is negative but
H and
S are positive
This option is incorrect.
Option 2)
G,
H and
S all are negative
This option is correct.
Option 3)
G and
H are negative but
S is positive
This option is incorrect.
Option 4)
G and
S are negative but
H is positive
This option is incorrect.