AbstractReaction accompanied mass transfer from fluid and solid spheres has been studied for creeping flow and a first order reaction.The results are presented graphically as Sherwood number plotted against Peclet number, with a dimensionless reaction rate factor as a parameter. At high values of the Peclet number the results approach the curves for physical mass transfer, while at low Peclet numbers the results may be predicted by the equations for reaction accompanied diffusions.The results were obtained by Yuge's method and by finite‐difference numerical methods. The latter methods had limited ranges of applicabilit