Is this true: The energy gaps between the vibrational energy levels of a molecule are smaller than the energy gaps between the electronic energy levels of a molecule.

True.

Explanation:

Vibrational molecular levels are those energy levels with which atoms are free to vibrate about each other. Like all vibrational motion, this level is governed by quantum mechanics.

The electronic energy levels of a molecule are determined by the orbit of the electron.

The electronic energy level gap are the greatest energy gaps in a molecule. This is because it is a lot more difficult for an electron to transition from one orbital to another. It is in fact easier for it to vibrate about its mean position than for it to jump from one orbit into another.

Furthermore, in order of band gap size, the various energy levels can further be organized below:

Rotational Transition < Vibrational Transition < Electronic Transition

   1-20 cm-1                      2000-4000 cm-1         10000-50000 cm-1      

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.