biphenyl and hexane would not hydrogen bond because they are both nonpolar right?
right AND they have no N, O, or F atoms.
Yes, you are correct. Biphenyl and hexane are both nonpolar molecules and do not exhibit hydrogen bonding.
To understand why, let's first clarify what hydrogen bonding is. Hydrogen bonding is a special type of intermolecular force that occurs between molecules containing hydrogen atoms bonded to highly electronegative elements like oxygen, nitrogen, or fluorine. This occurs when the hydrogen atom becomes partially positively charged due to the electronegativity difference, and it forms an attractive interaction with another electronegative atom in a neighboring molecule.
In the case of biphenyl and hexane, neither molecule contains hydrogen bonded to an electronegative atom such as oxygen or nitrogen. Biphenyl is composed of two benzene rings connected by a single bond, while hexane consists of a chain of six carbon atoms with hydrogen atoms attached to each carbon atom.
Since both biphenyl and hexane lack hydrogen atoms bonded to electronegative atoms, they cannot participate in hydrogen bonding. Instead, the intermolecular forces in these molecules are predominantly London dispersion forces, also known as van der Waals forces. London dispersion forces arise due to temporary fluctuations in electron density around molecules, causing temporary dipoles that induce dipoles in neighboring molecules.
These London dispersion forces are relatively weak compared to hydrogen bonding. Therefore, biphenyl and hexane do not form hydrogen bonds and are considered nonpolar substances.