All GRE Subject Test: Chemistry Resources
Example Question #1 : Hydrogen Bonding
Which of the following molecules is not capable of hydrogen bonding?
A molecule is capable of hydrogen bonding when a hydrogen atom is attached to a nitrogen, oxygen, or fluorine atom in the molecule. Methanal consists of a central carbon bound to two hydrogen atoms and a double bond with an oxygen atom. The hydrogen atoms are bound only to the carbon, and thus cannot form hydrogen bonds.
Hydrofluoric acid, ethanol, and ammonia are all capable of hydrogen bonding.
Example Question #2 : Hydrogen Bonding
Which compound exhibits hydrogen bonding?
Hydrogen bonding occurs between a hydrogen atom and an atom that has a high electronegativity such as fluorine, oxygen, or nitrogen. In this case, the only compound that exhibits hydrogen bonding is water, which has a hydrogen bonded to an oxygen atom. Note that in most cases hydrogen bonding is intermolecular, but in some cases, hydrogen bonding can occur intramolecularly.