The Raman spectrum of sulphur dioxide in different states

The influence of the state of matter on the three vibrations of sulphur dioxide has been studied. For that reason the Raman spectra of gaseous SO2 at 12 atmospheres, of liquid SO2 at 40° and 70°, of solutions of SO2 in water and of mixtures of SO2 with CCl4 (and SO3) were investigated. The difference between equation image gas and equation image liquid for the strongest Raman line of SO2, is equal to 6 cm−1. This is to be ascribed to the action of the electrostatic fields of the dipole molecules in the liquid. For solutions in water (at 50°), the dissolved SO2 is in a state comparable with the gaseous one. The concentration of H2SO3 in the solution can only be small. For the mixtures only small displacements of the Raman lines have been The spectrum of the mixtures consists in first approximation of a superposition of the spectra of the two components. The experimental arrangement used, is described in detail.