Twelve alkylsilanes have been synthesized and the following physical properties were measured: boiling point, freezing point, index of refraction, molecular weight and density. Vinylsilane and isobutylsilane are reported for the first time. Vapor pressures were measured using a static system, and the heats of vaporization were calculated from the data. By the use of a special sample filling technique, it was possible to measure the heats of ...