The boiling points of four para-derivatives of phenol are:
How can we compare the boiling points of p-nitrophenol and p-aminophenol?
Apart from the hydroxyl group, p-nitrophenol has two oxygen atoms to form inter-molecular H-bonding. Whereas, p-aminophenol has a nitrogen atom and two hydrogen atoms to form inter-molecular H-bonding. Also, the molecular mass of p-nitrophenol is more than that of p-aminophenol.