Question

The correct statement about the mixture of phenol and aniline are

• A. $A-A$ and $B-B$ interactions are weaker than $A-B$ interactions
• B. it forms a maximum boiling azeotrope
• C. $\Delta H_{\text {mix }} > 0$
• D. volume of mixture is lesser than zero

Answer 1

Answer: (A), (B), (D)

In the mixture of phenol and aniline, the intermolecular hydrogen bonding between phenolic proton and lone pair on $N$-atom of aniline is stronger than the respective
intermolecular hydrogen bonding between two same molecules.
Thus, their mixture shows negative deviation from Raoult's law.
For such mixtures, $\Delta H_{\text {mix }}<0$ and $\Delta V_{\text {mix }}< 0$
It forms a maximum boiling azeotrope.