H bonding occurs in H2O due to larger size of O-atom. — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: Boiling point of a covalent molecular compound is mainly determined by the strength and extent of intermolecular forces, of which hydrogen bonding is exceptionally strong. Step 2: Water forms an extensive network of 4 hydrogen bonds per molecule; methanol forms an average of 2 hydrogen bonds per molecule; and diethyl ether cannot form intermolecular hydrogen bonds due to the absence of a hydrogen atom bonded to an electronegative atom (N, O, F). Step 3: Thus, the extent of hydrogen bonding decreases from water (highest b.p.) to methanol to diethyl ether (lowest b.p. / absent), which corresponds to option (b).