Diffusion of Heavy into Light Water

Abstract

We have made measurements of the diffusion coefficient of heavy water (0.5–3.0 mol per cent) in aqueous solutions. The value provisionally obtained is about 9 × 10⁴ cm.²/sec. at 15° C. Since this is appreciably greater than is to be expected from the mass diffusion of water molecules (the largest recorded diffusion coefficient, namely, that of H₂ in H₂O, is about 4 × 10⁵ cm.²/sec.), it appears that an atomic interchange, such as has been suggested by Bernal and Fowler¹ to account for the abnormal electrolytic mobility of the hydrogen and hydroxyl ions, is involved.