The Stokes-Einstein law for diffusion in solution
Open Access
- 1 December 1924
- journal article
- Published by The Royal Society in Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character
- Vol. 106 (740) , 724-749
- https://doi.org/10.1098/rspa.1924.0100
Abstract
Einstein has shown that the relation between molecular movement and diffusion in a liquid may be expressed by the following equation, when the particles move independently of each other:— D=͞Δ 2 /2 t , (1) D being the diffusion constant and ͞Δ 2 the mean square of the deviation in a given direction in time t . Further, if it be assumed that the particles possess the same mean kinetic energy as gas molecules at the same temperature, the following equation holds ͞Δ = 2RT/N . t /C (2) where R is the gas constant, N Avogadro’s number, T the absolute temperature, and C a constant, which we might call the frictional resistance of the molecule. Hence, D = RT/N .1/C. (3) Under the foregoing assumptions equations (2) and (3) hold equally well for dissolved molecules and particles of greater dimensions.This publication has 0 references indexed in Scilit: