Which of the following form an ideal sơlution? I. Chloroethane and bromoethane II. Benzene and toluene III.…
Which of the following form an ideal sơlution?
I. Chloroethane and bromoethane
II. Benzene and toluene
III. $n$-hexane and $n$-heptane
IV. Phenol and aniline
I and II
I, II and III
II, III and IV
I and IV
Solution
Ideal solutions are the solutions which obey Raoult's law at all temperatures and pressures. The interactions of solute-solute, solvent-solvent and solute-solvent in these solutions are almost similar. No association/dissociation occurs in these solutions.
Mixture of phenol and aniline shows negative deviation from ideal behaviour and forms an azeotropic mixture. The phenol-aniline interactions are stronger than phenol-phenol or aniline-aniline interactions.
$\begin{aligned} & \Delta V_{\text {mixing }} < 0 \\ & \Delta H_{\text {mixing }}>0\end{aligned}$
Hence, it does not form an ideal solution.
Rest options (I), (II) and (III) form ideal solution.