The Differential Diffusion Constants of Hydrochloric and Sulphuric Acids

The differential diffusion constants of hydrochloric and sulphuric acids in aqueous solution at 25°C have been determined with Northrop-McBain diffusion cells. The range of concentration studied was 0.01–1.6 moles/liter for hydrochloric and 0.01–1.0 moles/liter for sulphuric. The relation previously proposed k=k0(1+c∂ ln f/∂c)·(η0/η) represents the variation of the diffusion constant with concentration reasonably closely, but the values of k0 required to fit the experimental results are not those predicted by the Nernst relation.