Question

The dipole-dipole interaction energy between rotation polar molecules is proportional to___, where 'r' is the distance between polar molecules.

• A. \(\frac{1}{r^4}\)
• B. \(\frac{1}{r^9}\)
• C. \(\frac{1}{r^3}\)
• D. \(\frac{1}{r^2}\)
• E. \(\frac{1}{r^6}\)

Answer 1

Answer: (E)

For polar molecules, the interaction energy between two dipoles is given by the formula: \[ U(r) = \frac{C}{r^6} \] where \( C \) is a constant and \( r \) is the distance between the molecules. This relationship arises due to the nature of dipole-dipole interactions, where the energy is inversely proportional to the sixth power of the distance between the dipoles.
Thus, the dipole-dipole interaction energy between rotating polar molecules is proportional to \( \frac{1}{r^6} \).

The correct option is (E) : \(\frac{1}{r^6}\)