Distinguish between the bonds between water molecules and those of octane?

Answer 1

water molecules have hydrogen bonds, however, octane has covalent bonds

Answer 2

Bonds between water molecules are called hydrogen bonds. A molecule that is highly polarizable and contains hydrogen bonded to a highly electronegative atom (like oxygen) coulld form a "bridge" bond with a neighbor molecule this is called hydrogen bond.

Octane is a linear molecule with a very low polarity and much higher MW than water, and it boils exacly at 100° like water. However the bonds between the molecule are just dipole-dipole bonds and instantaneous dipole-dipole bonds, normally called Van der Walls forces.

Recently some articles popped out claiming that hydrogen bond doesn't exist. And that van der Walls forces are much more powerful then it was thought before. (at least from a QM model point of view)