JEE Main · 2020 · 05 Sep 2020 · Shift 2 · Alcohols Phenols and Ethers

Boiling points follow the strength of intermolecular attraction. p-Cresol, held together only by the ordinary hydrogen bonding of its phenolic $-\mathrm{OH}$, boils lowest. p-Methoxyphenol comes next, its extra ether oxygen adding dipolar attraction and molar mass. p-Aminophenol, carrying both $-\mathrm{OH}$ and $-\mathrm{NH}{}_2$, forms an extended intermolecular hydrogen-bonded network and boils higher still. p-Nitrophenol, whose strongly polar nitro group reinforces intermolecular association, boils highest of the four. The increasing order is p-cresol $<$ p-methoxyphenol $<$ p-aminophenol $<$ p-nitrophenol.