Which among the following has highest melting point ?

Step-by-step solution

p-Nitrophenol has the highest melting point among the given compounds. In p-nitrophenol, there is strong intermolecular hydrogen bonding between the -OH group of one molecule and the -N O₂ group of another molecule. This leads to the association of molecules, requiring more thermal energy to break the crystal lattice. In contrast, o-nitrophenol exhibits intramolecular hydrogen bonding (chelation), which restricts molecular association and lowers its melting point. Phenol and p-cresol also exhibit intermolecular hyd