Temperature Dependence of Oxygen Diffusion in H2O and D2O

The diffusion coefficient of O2 in H2O and D2O has been determined as a function of temperature from −0.5 to 95 °C, using the Taylor dispersion technique with optical absorbance detection at 200 nm. Over this temperature range, significant deviation from both Arrhenius and Stokes−Einstein behavior is found. A practical interpolation formula for the H2O solvent is (T in Kelvin) log10D/cm2 s-1 = −4.410 + 773.8/T − (506.4/T)2 and, for the D2O solvent, log10D/cm2 s-1 = −4.706 + 903.6/T − (526.6/T)2. As a test of the apparatus, the diffusion coefficient of nitrobenzene in water was carefully measured and found to be 1.04 × 10-5 cm2 s-1 at 26 °C and 2.14 × 10-5 cm2 s-1 at 60.1 °C.