High Quality Content by WIKIPEDIA articles! All syntheses start from the perxenates, which are accessible from the xenates through two methods. One is the disproportionation of xenates to perxenates and xenon: 2 XeO2 4 XeO4 6 + Xe + O2 The other is oxidation of the xenates with ozone: 2 XeO2 4 + 4 e + 2 O3 2 XeO4 6 + 2 O2 Barium perxenate is reacted with sulfuric acid and the unstable perxenic acid is dehydrated to give xenon tetroxide:Ba2XeO6 + 2 H2SO4 2 BaSO4 + (H4XeO6 2 H2O + XeO4) The unstable perxenic acid slowly undergoes a disproportionation reaction to the xenic acid and oxygen:H4XeO6 1/2 O2 + H2XeO4 + H2O