Mixtures of organic compounds with mineral dust are ubiquitous in the atmosphere, whereas the formation pathways and hygroscopic behavior of these mixtures are not well understood. In this study, in situ DRIFTS, XRD, and a vapor sorption analyzer were used to investigate the heterogeneous reaction of acetic acid on α-Al₂O₃, MgO, and CaCO₃ particles under both dry and humid conditions while the effect of reactions on the hygroscopic behavior of these particles was also measured. In all cases, formation of acetate is significantly enhanced in the presence of surface water. However, the reaction extent varied with the mineral phase of these particles. For α-Al₂O₃, the reaction is limited to the surface with the formation of surface coordinated acetate under both dry and humid conditions. For MgO, the bulk of the particle is involved in the reaction and Mg(CH₃COO)₂ is formed under both dry and humid conditions, although it exhibits a saturation effect under dry conditions. In the case of CaCO₃, acetic acid uptake is limited to the surface under dry conditions while it leads to the decomposition of the bulk of CaCO₃ under humid conditions. While coordinated surface acetate species increased the water adsorption capacity slightly, the formation of bulk acetate promoted the water absorption capacity greatly. This study demonstrated that heterogeneous reaction between CH₃COOH and mineral dust is not only an important sink for CH₃COOH, but also has a significant effect on the hygroscopic behavior of mineral dust.