Hydrogen Bonding and the Boiling Points of Hydrides

ChemistryChemical BondingAges 15–16

A graph of the actual boiling points of the hydride series H₂O–H₂S–H₂Se–H₂Te, HF–HCl–HBr–HI, NH₃–PH₃–AsH₃–SbH₃ and CH₄–SiH₄–GeH₄–SnH₄ against period. Students switch each series on or off and tap a point to see a molecular model: H₂O, HF and NH₃ have hydrogen bonds (dashed lines) between their molecules, so they boil unusually high compared with the extrapolated trend, whereas H₂S, HCl and CH₄ have only van der Waals forces.