The boiling points of HF, H2O and NH3 increase in the order of
Answer Details
The boiling point of a substance is the temperature at which it changes its state from liquid to gas. The boiling point of a substance is dependent on its intermolecular forces, which include van der Waals forces, hydrogen bonding, and dipole-dipole interactions. The stronger the intermolecular forces, the higher the boiling point. In the given options, NH3, H2O, and HF are all polar molecules, which exhibit hydrogen bonding, the strongest of intermolecular forces. Among the given options, HF molecules have the strongest hydrogen bonding as compared to H2O and NH3 molecules. Therefore, HF has the highest boiling point among the given options. Similarly, NH3 molecules have the weakest hydrogen bonding as compared to HF and H2O molecules, so NH3 has the lowest boiling point among the given options. Therefore, the order of increasing boiling points is NH3 < HF < H2O. Hence, the correct option is: "NH3 < HF < H2O".