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This paper presents a study of mass transfer in an electrochemical cell using the limiting current technique. The liquid-wall mass transfer coefficient is obtained in homogeneous flow employing a coaxially placed string of hemispheres as turbulent promoter by varying the geometric variables of the promoter (pitch, characteristic length, rod diameter) and superficial liquid velocity. Analysis of the data reveals that the mass transfer coefficient increases with increase in characteristic length and rod diameter but decreases with increase in pitch. The mass transfer data were correlated by non linear regression to yield an equation in j D -Re format. List of symbolsA Area of the reacting surface [m 2 ] C 0 Concentration of ferricyanide ion [kmol/m 3 ] d c Column diameter [cm] d b Characteristic Length = diameter of the ball [cm] d r Diameter of the rod [cm] D L Diffusivity of reacting ion [m 2 /s] F Faraday constant [C/mol of electrons] i L Limiting current [A] k L Mass transfer coefficient [m/s] p Pitch of the hemispherical balls [cm] V Superficial Liquid Velocity [m/s] X Longitudinal distance [m] Z Number of electrons released or consumed during the reaction j D Mass transfer factor = k L V Sc 2=3 [-] Re Reynolds number = qd c V l [-] Sc Schmidt number = l qD L [-] l Viscocity of electrolyte [kg-m/s] q Density of the electrolyte [kg/m 3 ]

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