The Limiting Negative Pressure of Acetic Acid, Benzene, Aniline, Carbon Tetrachloride, and Chloroform

Abstract

The limiting negative pressure of acetic acid, benzene, aniline, carbon tetrachloride, and chloroform has been measured in relation to temperature. A centrifugal method was employed, the liquid being contained in a capillary tube, the ends or legs of which were bent sharply back parallel to the straight central part. The tube was cemented to a horizontal spinner, with its midpoint intersecting the spin axis. Both ends of the tube were open, which facilitated filling and cleaning. The volume of liquid was so chosen that the menisci were located in the legs of the tube near the bends. The maximum values observed were: CH₃COOH, −288 bars; C₆H₆, −150 bars; C₆H₅NH₂, −300 bars; CCl₄, −276 bars; CHCl₃, −317 bars. Excepting benzene, the limiting negative pressure of these liquids has not heretofore been measured. All except benzene equal or exceed that of water (−275 bars). Acetic acid, benzene, and aniline show a decrease in the limiting negative pressure as the freezing point is approached, like water, but the effect is much less marked. The higher values observed for the polar liquids in comparison with their nonpolar relatives suggests that the dipoles are contributing markedly to the cohesion of the liquid. An investigation of the cis‐ and trans‐forms of the same liquid is now under way.