Ortho–Nitrophenol is less soluble in water than p– and m– Nitrophenols because :
1 o–Nitrophenol is more volatile in steam than those of m – and p–
isomers2 o–Nitrophenol shows Intramolecular H–
bonding3 o–Nitrophenol shows Intermolecular H–
bonding4 Melting point of o–Nitrophenol is lower than those of m–and p–isomers.