Thermodynamics and Thermochemistry - Result Question 43
43. Benzene and naphthalene form an ideal solution at room temperature. For this process, the true statement(s) is (are)
(2013 Adv.)
(a) $\Delta G$ is positive
(b) $\Delta S _{\text {system }}$ is positive
(c) $\Delta S _{\text {surroundings }}=0$
(d) $\Delta H=0$
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Answer:
Correct Answer: 43. (b, c, d)
Solution:
PLAN: When an ideal solution is formed process is spontaneous thus According to Raoult’s law, for an ideal solution
$ \Delta H=0, \Delta V _{\min }=0 $
From the relation
$\Delta G=\Delta H-T \Delta S$
Since,
$ \Delta H=0 $
$\therefore \quad \Delta G=-ve$
i.e. less than zero. and $\Delta S _{\text {surroundings }}=0$
Therefore, $\quad \Delta S _{\text {sys }}=+$ ve
i.e. more than zero.