A method for making a mixture containing acetic acid, acetaldehyde, and ethanol as the pricipal products, which process comprises reacting carbon monoxide and hydrogen at an elevated temperature and at an elevated pressure in the presence of a supported catalyst prepared by impregnating a carrier with a salt or complex of rhodium and, as a promotor, with at least one non-oxidic compound of an element having an atomic number of 21, 39, or 58 to 71.