Molybdenum trioxide

Molybdenum trioxide
Names
	IUPAC name Molybdenum trioxide
	Other names Molybdic anhydride; Molybdite; Molybdic trioxide; Molybdenum(VI) oxide
Identifiers
CAS Number	1313-27-5 anhydrous ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:30627;
ChemSpider	14118;
ECHA InfoCard	100.013.823
EC Number	215-204-7;
PubChem CID	14802;
UNII	22FQ3F03YS ;
UN number	3288
CompTox Dashboard (EPA)	DTXSID7020899 ;
	InChI InChI=1S/Mo.3O Key: JKQOBWVOAYFWKG-UHFFFAOYSA-N;
	SMILES O=[Mo](=O)=O;
Properties
Chemical formula	MoO3
Molar mass	143.95 g·mol−1
Appearance	yellow solid
Odor	odorless
Density	4.70 g/cm3
Melting point	802 °C (1,476 °F; 1,075 K)
Boiling point	1,155 °C (2,111 °F; 1,428 K)(sublimes)
Solubility in water	1.066 g/L (18 °C) ; 4.90 g/L (28 °C) ; 20.55 g/L (70 °C)
Band gap	>3 eV (direct)
Magnetic susceptibility (χ)	+3.0·10−6 cm3/mol
Structure
Crystal structure	Orthorhombic, oP16
Space group	Pnma, No. 62
Lattice constant	a = 1.402 nm, b = 0.37028 nm, c = 0.39663 nm
Formula units (Z)	4
Coordination geometry	see text
Thermochemistry
Heat capacity (C)	75.0 J K−1 mol−1
Std molar; entropy (S⦵298)	77.7 J K−1 mol−1
Std enthalpy of; formation (ΔfH⦵298)	−745.1 kJ/mol
Gibbs free energy (ΔfG⦵)	-668.0 kJ/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H319, H335, H351
Precautionary statements	P201, P202, P261, P264, P271, P280, P281, P304+P340, P305+P351+P338, P308+P313, P312, P337+P313, P403+P233, P405, P501
NFPA 704 (fire diamond)	3 0 OX
Flash point	Non-flammable
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	125 mg.kg (rat, oral); 2689 mg/kg (rat, oral)
LDLo (lowest published)	120 mg Mo/kg (rat, oral); 120 mg Mo/kg (guinea pig, oral)
LC50 (median concentration)	>5840 mg/m3 (rat, 4 hr)
Related compounds
Other cations	Chromium trioxide; Tungsten trioxide
Related molybdenum oxides	Molybdenum dioxide; "Molybdenum blue"
Related compounds	Molybdic acid; Sodium molybdate
	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

Molybdenum trioxide describes a family of inorganic compounds with the formula MoO₃(H₂O)_n where n = 0, 1, 2. The anhydrous compound is produced on the largest scale of any molybdenum compound since it is the main intermediate produced when molybdenum ores are purified. The anhydrous oxide is a precursor to molybdenum metal, an important alloying agent. It is also an important industrial catalyst. It is a yellow solid, although impure samples can appear blue or green.

Molybdenum trioxide occurs as the rare mineral molybdite.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.