Out of the isomeric nitrophenols, the ortho-isomer is steam volatile while the para-isomer is not. W — Alcohols Phenols and Ethers Chemistry Question

💡 Solution & Explanation

o-Nitrophenol forms intramolecular hydrogen bonds (chelation) between the $-OH$ and ortho $-NO_2$ groups, acting as discrete volatile units. p-Nitrophenol forms extensive intermolecular H-bonds, associating into large networks that are not steam volatile.