Vapor-liquid equilibria for binary mixtures of polar solvents with either carbon dioxide, ethane, or ethene were determined with a newly designed apparatus. Bubble-point curves were determined for three different temperatures. The densities of the liquid phases were also obtained. From these data the volume expansions of the liquid phases were calculated. The results show large differences in the volume expansions, depending on the binary system investigated. The binary systems with carbon dioxide show an interesting density behavior, which has no equivalent in the ethane or ethene systems. The bubble-point curves were modeled with the Peng-Robinson equation of state (EOS).