Question from a viewer: Water, H2O, boils at 100 degree Celsius ; ethanol, C2H5OH, boils at 78 degree Celsius, and ammonia NH3 boils at -33 degree Celsius. Rank these three compounds in order from weakest to strongest intramolecular interaction. Explain how you get your answer.
Higher boiling point = stronger intermolecular forces.
Water boils at a higher temperature because its hydrogen-oxygen bonds cause hydrogen bonding, which is a strong intermolecular force that makes the molecules stick to each other. This means you have to add more energy (heat) to get them to separate and boil.