Molecular formula: MoO₃
Molar mass: 143.94 g/mol
EINECS: 215-204-7
Melting point: 795 °C(lit.)
Water solubility: 0.5 g/L (20 ºC)
Appearance: Colorless to white or yellow odorless solid
Product categories of Molybdenum trioxide(CAS NO.1313-27-5): Inorganics
Structure of Molybdenum trioxide(CAS NO.1313-27-5):
                                                                        
H-Bond Donor: 0
H-Bond Acceptor: 3
IUPAC Name: Trioxomolybdenum
Canonical SMILES: O=[Mo](=O)=O
InChI: InChI=1S/Mo.3O 
InChIKey: JKQOBWVOAYFWKG-UHFFFAOYSA-N

Its chief application is as an oxidation catalyst and as a raw material for the production of molybdenum metal. Molybdenum trioxide(CAS NO.1313-27-5) is used to manufacture molybdenum metal, which serves as an additive to steel and corrosion-resistant alloys. The relevant conversion entails treatment is hydrogen at elevated temperatures.It is of interest in electrochemical devices and displayswith its layered structure and the ease of the Mo(VI)/Mo(V) couple.And it is also a component of the co-catalyst used in the industrial production of acrylonitrile by the oxidation of propene and ammonia.

Molybdenum trioxide(1313-27-5) is produced on the largest scale of any molybdenum compound, and produced industrially by burning molybdenum disulfide (2 MoS₂ + 7 O₂ → 2 MoO₃ + 4 SO₂ ).The laboratory synthesis entails the acidification of aqueous solutions of sodium molybdate with perchloric acid (Na₂MoO₄ + H₂O + 2 HClO₄ → MoO₃(H₂O)₂ + 2 NaClO₄ ).

Reported in EPA TSCA Inventory.

Poison by ingestion, subcutaneous, and intraperitoneal routes. Human systemic effects by inhalation: pulmonary fibrosis and cough. Questionable carcinogen with experimental neoplastigenic data. A powerful irritant. Explodes on contact with molten magnesium. Violent reaction with interhalogens (e.g., bromine pentafluoride, chlorine trifluoride). Incandescent reaction with hot sodium, potassium, or lithium. When heated to decomposition it emits toxic fumes of Mo. See also MOLYBDENUM COMPOUNDS.
Hazard Codes: Xn,Xi
Risk Statements: 36/37-48/20/22
20:  Harmful by inhalation
22:  Harmful if swallowed
36:  Irritating to the eyes
37:  Irritating to the respiratory system
48:  Danger of serious damage to health by prolonged exposure
Safety Statements: 22-23-25
22:  Do not breathe dust
23:  Do not breathe gas/fumes/vapor/spray (appropriate wording to be specified by the manufacturer) 
25:  Avoid contact with eyes

OSHA PEL: TWA 5 mg(Mo)/m³
ACGIH TLV: TWA Soluble Compounds: TWA 0.5 mg(Mo)/m³ Confirmed Animal Carcinogen with Unknown Relevance to Humans

 Molybdenum trioxide ,its cas register number is 1313-27-5.It also can be called Molybdenum(VI) oxide ; Molybdic trioxide ; Molybdic oxide ; Molybdic anhydride ; Trioxomolybdenum and molybdenum, trioxo- .It is hazardous,so the first aid measures and others should be known.Such as: When on the skin: first,should  flush skin with plenty of water immediately for at least 15 minutes while removing contaminated clothing. Secondly,Get shoesmedical aid . Or in the eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids.Then get medical aid soon.While ,it's Inhaled: Remove from exposure and move to fresh air immediately.Give artificial respiration while not breathing. When breathing is difficult, give oxygen. And as soon as to get medical aid. Then you have the ingesting of the product : Wash mouth out with water,and get medical aid immediately.Notes to physician: Treat supportively and symptomatically.In addition, Molybdenum trioxide(CAS NO.1313-27-5) can be stable under normal temperature and pressure conditions.It is not compatible with strong oxidizing agents, strong acids, active metals, bromine trifluoride, chlorine trifluoride, magnesium, lithium, and you must not take it with incompatible materials.