The modeling and design of reactive absorption is based on a theoretical description of reaction and mass transport in multicomponent systems. The multicomponent nature of these phenomena leads to complex process behavior due to the superposition of many driving forces-multicomponent diffusion, chemical interactions, convective flows, multicomponent thermodynamic interplay, etc. For this reason, an adequate theoretical description of the multicomponent reactive systems calls for the application of the Maxwell-Stefan equations and, further, for the use of matrix coupled mass-transfer equations together with the relevant reaction kinetics. On this basis, a two-phase, gas-liquid system is considered and a general model is developed for its design. Reactions in both liquid and gas phases are taken into account, and both the film and bulk reaction mechanisms are allowed for. The transport equation describing the film phenomena is solved analytically by using a linearization of the reaction term. The model is applied to the description of NO, absorption. A comparison of the experimental and theoretical results demonstrated their good agreement.