$2XeO{F_4}\, + \, Si{O_2} \, \to \,2Xe{O_2}{F_2}\, + \,Si{F_4}$
$2Xe{O_2}{F_2}\, + \,Si{O_2}\, \to \,\mathop {2Xe{O_3}}\limits_{(\exp losive\,)} \, + \,Si{F_4}$