Xenon trioxide is an unstable
compound
Compound may refer to:
Architecture and built environments
* Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall
** Compound (fortification), a version of the above fortified with defensive struc ...
of
xenon
Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...
in its +6
oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...
. It is a very powerful
oxidizing agent
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxi ...
, and liberates oxygen from water slowly, accelerated by exposure to sunlight. It is dangerously explosive upon contact with organic materials. When it detonates, it releases xenon and oxygen gas.
Chemistry
Xenon trioxide is a strong oxidising agent and can oxidise most substances that are at all oxidisable. However, it is slow-acting and this reduces its usefulness.
Above 25 °C, xenon trioxide is very prone to violent explosion:
:2 XeO
3 → 2 Xe + 3 O
2 (Δ''H''
f = −403
kJ/
mol)
When it dissolves in water, an acidic solution of
xenic acid is formed:
:XeO
3(aq) + H
2O → H
2XeO
4 H
+ +
This solution is stable at room temperature and lacks the explosive properties of xenon trioxide. It oxidises
carboxylic acids quantitatively to
carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...
and
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
.
Alternatively, it dissolves in alkaline solutions to form ''xenates''. The 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. Solid perxenates containing have been isolated by reacting with an aqueous solution of hydroxides. Xenon trioxide reacts with inorganic fluorides such as KF, RbF, or CsF to form stable solids of the form .
Physical properties
Hydrolysis of
xenon hexafluoride
Xenon hexafluoride is a noble gas compound with the formula XeF6. It is one of the three binary fluorides of xenon, the other two being XeF2 and XeF4. All known are exergonic and stable at normal temperatures. XeF6 is the strongest fluorinati ...
or
xenon tetrafluoride yields a solution from which colorless XeO
3 crystals can be obtained by evaporation. The crystals are stable for days in dry air, but readily absorb water from humid air to form a concentrated solution. The crystal structure is
orthorhombic with ''a'' = 6.163 Å, ''b'' = 8.115 Å, ''c'' = 5.234 Å, and 4 molecules per unit cell. The density is 4.55 g/cm
3.
Safety
XeO
3 should be handled with great caution. Samples have detonated when undisturbed at room temperature. Dry crystals react explosively with cellulose.
References
External links
Webelements periodic table: page on Xenon(VI) oxide
{{Oxides
Oxides
Xenon(VI) compounds
Inorganic compounds