Question

Benzene and naphthalene form an ideal solution at room temperature. For this process, the true statement(s) is(are):

• A. $\Delta G$ is positive
• B. $\Delta S_{system}$ is positive
• C. $\Delta S_{surroundings}=0$
• D. $\Delta H=0$

Answer 1

Answer: (B), (C), (D)

The correct options are
B $\Delta S_{system}$ is positive
C $\Delta S_{surroundings}=0$
D $\Delta H=0$

When an ideal solution is formed process is spontaneous

According to Raoult's law, for an ideal solution

$\Delta H=0$

$\Delta V_{mix}=0$

Since there is no exchange of heat energy between system and surroundings

$\Delta S_{surroundings}=0$

$\Delta S_{sys.}=+ve$

$\therefore$ From the relation

$\Delta G=\Delta H–T\Delta S$

$\Delta G=-ve$

Hence, the correct options are $B$, $C$ and $D$