The solid-liquid mass transfer characteristics of an in-line tube bank immersed in a gas-liquid bubble column were investigated by measuring the rate of diffusion-controlled dissolution of copper surface in acidified dichromate solution. Variables studied were the number of rows in the tube bank, physical properties of the solution, and nitrogen flow rate. The mass transfer coefficient was found to increase with increasing nitrogen flow rate. Increasing the number of rows in the tube bank was found to decrease the mass transfer coefficient. The data were correlated for the following conditions: 0.0021 < Fr.Re < 0.1603, 1 < Nr < 5 and 850 < Sc < 1370 by the equation J = 0.15 ( Fr.Re)(-0.15). Comparison was made between the present mass transfer data and previous heat and mass transfer studies conducted in packed and empty bubble columns.