Final answer:
Hydrogen bonds are significantly weaker than covalent bonds, which impacts the physical properties of substances and is critical for biological molecule stability. With typical dissociation energies between 15-25 kJ/mol, these bonds influence boiling points and the unique properties of water.
Step-by-step explanation:
The result of hydrogen bonds being much weaker than covalent or ionic bonds is significant in the way molecules interact with one another. For instance, the physical properties of substances like water, which is capable of forming multiple hydrogen bonds, are largely influenced by these weaker bonds. A hydrogen bond typically has a dissociation energy of about 15-25 kJ/mol, which, while much less than the energy needed to break a covalent bond (e.g., the O-H covalent bond at 492 kJ/mol), is still stronger than other van der Waals forces. This relative weakness allows for the unique properties of water, affects the boiling points of similar compounds such as HF and NH3, and is critical in stabilizing the structures of important biological molecules like proteins and DNA.