Uranium dioxide

Uranium dioxide
Names
	IUPAC names Uranium dioxide; Uranium(IV) oxide
	Other names Urania; Uranous oxide
Identifiers
CAS Number	1344-57-6 ;
3D model (JSmol)	Interactive image;
ChemSpider	10454 ;
ECHA InfoCard	100.014.273
EC Number	215-700-3;
PubChem CID	10916;
RTECS number	YR4705000;
UNII	L70487KUZO ;
CompTox Dashboard (EPA)	DTXSID8061682 ;
	InChI InChI=1S/2O.U Key: FCTBKIHDJGHPPO-UHFFFAOYSA-N;
	SMILES O=[U]=O;
Properties
Chemical formula	UO2
Molar mass	270.03 g/mol
Appearance	black powder
Density	10.97 g/cm3
Melting point	2,865 °C (5,189 °F; 3,138 K)
Solubility in water	insoluble
Structure
Crystal structure	Fluorite (cubic), cF12
Space group	Fm3m, No. 225
Lattice constant	a = 547.1 pm
Coordination geometry	Tetrahedral (O2−); cubic (UIV)
Thermochemistry
Std molar; entropy (S⦵298)	78 J·mol−1·K−1
Std enthalpy of; formation (ΔfH⦵298)	−1084 kJ·mol−1
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H330, H373, H410
Precautionary statements	P260, P264, P270, P271, P273, P284, P301+P310, P304+P340, P310, P314, P320, P321, P330, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	4 0 0 OX
Flash point	N/A
Safety data sheet (SDS)	ICSC 1251
Related compounds
Other anions	Uranium(IV) sulfide ; Uranium(IV) selenide
Other cations	Protactinium(IV) oxide ; Neptunium(IV) oxide
Related uranium oxides	Triuranium octoxide; Uranium trioxide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Uranium dioxide or uranium(IV) oxide (UO₂), also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear reactors. A mixture of uranium and plutonium dioxides is used as MOX fuel. Prior to 1960, it was used as yellow and black color in ceramic glazes and glass.

^ Leinders, Gregory; Cardinaels, Thomas; Binnemans, Koen; Verwerft, Marc (2015). "Accurate lattice parameter measurements of stoichiometric uranium dioxide". Journal of Nuclear Materials. 459: 135–42. Bibcode:2015JNuM..459..135L. doi:10.1016/j.jnucmat.2015.01.029. S2CID 97183844.
^ ^a ^b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 978-0-618-94690-7.

[lp-1] Leinders, Gregory; Cardinaels, Thomas; Binnemans, Koen; Verwerft, Marc (2015). "Accurate lattice parameter measurements of stoichiometric uranium dioxide". Journal of Nuclear Materials. 459: 135–42. Bibcode:2015JNuM..459..135L. doi:10.1016/j.jnucmat.2015.01.029. S2CID 97183844.

[b1-2] Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 978-0-618-94690-7.

[1]

[2]

Names

IUPAC names Uranium dioxide Uranium(IV) oxide
Other names Urania Uranous oxide
Identifiers
CAS Number	1344-57-6^Y
3D model (JSmol)	Interactive image
ChemSpider	10454^Y
ECHA InfoCard	100.014.273
EC Number	215-700-3
PubChem CID	10916
RTECS number	YR4705000
UNII	L70487KUZO^Y
CompTox Dashboard (EPA)	DTXSID8061682
InChI InChI=1S/2O.U Key: FCTBKIHDJGHPPO-UHFFFAOYSA-N
SMILES O=[U]=O
Properties
Chemical formula	UO₂
Molar mass	270.03 g/mol
Appearance	black powder
Density	10.97 g/cm³
Melting point	2,865 °C (5,189 °F; 3,138 K)
Solubility in water	insoluble
Structure
Crystal structure	Fluorite (cubic), cF12
Space group	Fm3m, No. 225
Lattice constant	a = 547.1 pm ^[1]
Coordination geometry	Tetrahedral (O²⁻); cubic (U^IV)
Thermochemistry
Std molar entropy (S^⦵₂₉₈)	78 J·mol⁻¹·K⁻¹^[2]
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	−1084 kJ·mol⁻¹^[2]
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H330, H373, H410
Precautionary statements	P260, P264, P270, P271, P273, P284, P301+P310, P304+P340, P310, P314, P320, P321, P330, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	4 0 0 OX
Flash point	N/A
Safety data sheet (SDS)	ICSC 1251
Related compounds
Other anions	Uranium(IV) sulfide Uranium(IV) selenide
Other cations	Protactinium(IV) oxide Neptunium(IV) oxide
Related uranium oxides	Triuranium octoxide Uranium trioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references