An,experimental investigation was made to measure inter-facial area, a, and liquid-side volumetric mass transfer coefficient; k(L)a, in a downflow bubble column by chemical methods viz., absorbing CO2 in aqueous sodium, hydroxide and sodium carbonate/bicarbonate buffer solution respectively. The effect of gas and liquid flowrate and nozzle sizes on 9 and k(L)a were investigated. The experimental data obtained in the present system were analyzed and correlations were developed to predict a and k(L)a in terms of superficial gas velocity. The variation of a and k(L)a with specific power input were shown in graphical plot and compared with other gas-liquid systems.