The xenate ion, [HXeO4]-, slowly decomposes in alkaline solution to give perxentate (XeO64-) 2HXeO4- + 2OH- = XeO64- + Xe + O2 + 2H2O Solution The xenate ion, [HXeO4]-, slowly decomposes in alkaline solution to give perxentate (XeO64-) 2HXeO4- + 2OH- = XeO64- + Xe + O2 + 2H2O.