Surface Chemistry - Result Question 24
25. Spontaneous adsorption of a gas on solid surface is an exothermic process, because
(2004, 1M)
(a) $\Delta H$ increases for system
(b) $\Delta S$ increases for gas
(c) $\Delta S$ decreases for gas
(d) $\Delta G$ increases for gas
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Answer:
Correct Answer: 25. (c)
Solution:
$\Delta G=\Delta H-T \Delta S$
As gas is adsorbed on surface of solid, entropy decreases, i.e. $\Delta S<0$. Therefore, for $\Delta G<0, \Delta H$ must be negative.
BETA
