Xenon trioxide is an unstable compound of xenon in its +6 oxidation state. It is a very powerful oxidizing agent, and liberates oxygen from water slowly (and xenon), accelerated by exposure to sunlight. It is dangerously explosive upon contact with organic materials. When it detonates, it releases xenon and oxygen gas.
Xenon trioxide is a strong oxidizing agent and can oxidize most substances that are susceptible. However, it is slow-acting and this reduces its usefulness.
When it dissolves in water, an acidic solution of xenic acid is formed:
Alternatively, it dissolves in alkaline solutions to form xenates. The HXeO anion is the predominant species in xenate solutions. These are not stable and begin to disproportionate into perxenates (+8 oxidation state) and xenon and oxygen gas.