Multipak 1 and 2 and Katapak S-250 and S-500 reactive packings were studied in CO2-water-air and NH3-water-air systems, 1 atm, room temp., to det. the liq.-phase and gas-phase mass transfer in a 1-m packed bed 250-mm (phi) column. Pressure drop through dry and irrigated packing was detd. The mass-transfer coeffs. were detd. in terms of the Sherwood and Reynolds correlations. As the sp. surface of packing was increased, mass transport rose only slightly. Flooding and axial dispersion appeared. Katapak S-250 and S-500 were hydrodynamically stable and their operating ranges were closely related. The operating ranges of the 1 and 2 were narrower and their operation was less stable. Close to the flooding ps., local barbotage appeared in the areas of contact of packing segments.