The reaction between potassium iodate and molybdenum(VI) oxide in mixtures of different mole ratios has been investigated employing TG and DTA techniques in static air atmosphere. The products are characterised by infrared spectroscopy, chemical analysis and X-ray diffraction studies. The studies indicate the formation of mono-, di-, tri- and tetramolybdates of potassium from mixtures with 2:1, 1:1, 2:3 and 1:2 mole ratios of KlO3:MoO3. The kinetics of the reaction was followed and the energy of activation values were computed. © 1989 Wiley Heyden Ltd., Chichester and Akadémiai Kiadó, Budapest.