Question

(ii) how many numbers of fundamental vibrations possible for water and benzene

Answer 1

The benzene molecule contains 12 atoms (Fig. lb) and the intermolecular vibrations can be described with 42 internal coordinates : 30 for in-plane vibrations (6 CH stretching, 6 CC stretching, 6 CCC bending and 12 CCH bending coordinates and 12, for out-of-plane vibrations (6 wagging and 6 torsional coordinates).