This work deals with the steady-state solution of a rotating disk flow, coupled, through the fluid viscosity, to the mass-concentration field of chemical species. The configuration refers to electrochemical cells where the working electrode consists of an iron rotating rod which is dissolved into the electrolyte, a sulfuric acid solution. Dissolution of the electrode gives rise to a thin concentration boundary layer, which, together with the potential applied to the electrode, results in an increase in the fluid viscosity and a decrease in the diffusion coefficient close to the electrode surface, both affecting the current. A phenomenological law is assumed, relating the fluid viscosity to the concentration of relevant chemical species. Parameters appearing in this law are evaluated based on experimental electrochemical data. The steady-state solution is obtained by solving the coupled hydrodynamic and mass-concentration equations.