It has been found that sulfur dioxide solubility in organic solvents can be well-correlated by Lewis basicity numbers, Mixtures of sulfur dioxide and solvent (N-methylpyrrolidone (NMP), N,N’-(dimethylpropylene)urea (DMPU) and methyldiethanolamine (MDEA)) have been prepared in a 1:1 male ratio at low temperatures. The melting points of the mixtures are measured, and the mixtures have been analyzed by infrared, ultraviolet-visible, and nuclear magnetic resonance spectroscopy. The solubility of sulfur dioxide has been measured in NMP and DMPU at 25 degrees C. At sulfur dioxide concentrations of 0.2-0.6 kPa, the solubility is determined using a continuous stirred tank reactor, The absorption of sulfur dioxide proved to be completely reversible. A model where physical and chemical interactions are incorporated showed good correlation with the experimental results.