The unexpectedly high solubility of water in cryogenic liquids

Abstract

The solubility of H2O in cryogenic liquids, such as liquid nitrogen (LIN), liquid oxygen (LOX) and liquid methane, would be expected to be extremely low1,2. Recent work using gravimetric methods suggested that the solubility of H2O in liquid nitrogen could be as high as 10 p.p.m. or 10−5 mole fraction3. This is many orders of magnitude greater than that expected, which is 10−16 to 10−18 mole fraction (B. Jarosz, E. Szcepaniec-Cieciak and Z. Wojtaszek, personal communication). We confirm here the unexpectedly high solubility of H2O in LIN (10.0×10−6 mole fraction), LOX (10.1×10−6 mole fraction) and liquid methane (60×10−6 mole fraction) at their respective normal boiling points by using Fourier transform IR spectroscopy. We have also eliminated the possibilities of experimental artefacts via parallel experiments with D2O.