Question

Compare the rotational and translational energies of a molecule of a keto form of 2,4-pentanedione and explain why the vibrational energy is different from these energies?

Answer 1

Vibrational energy consists of energy due to different modes of vibrations.

The bonds in the bond can be easily vibrated by the slight change in the bond length on saturated bonds. i.e Stretching of the bonds. This again presents two cases. Symmetrical and Asymmetrical stretching.

Then due to the difference in bond angles among the group of entities present in the molecule. i.e Bending.

In rotational and transitional energies the bond length is not changed. While vibrational energy is of various forms including Twisting, Wagging and Rocking.

Also, the keto form is in equilibrium with enol form.The enol form has a C_2v symmetry.