Search results
Results from the WOW.Com Content Network
Molybdenum trioxide describes a family of inorganic compounds with the formula MoO 3 (H 2 O) 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 ...
Heating ammonium orthomolybdate solid or treatment with acid gives molybdenum trioxide. Such reactions proceed via ammonium dimolybdate. This equilibrium is exploited in the purification of molybdenum from its ores. Aqueous solutions of ammonium orthomolybdate react with hydrogen sulfide to give ammonium tetrathiomolybdate:
Ammonium heptamolybdate is the inorganic compound whose chemical formula is (NH 4) 6 Mo 7 O 24, normally encountered as the tetrahydrate.A dihydrate is also known. It is a colorless solid, often referred to as ammonium paramolybdate or simply as ammonium molybdate, although "ammonium molybdate" can also refer to ammonium orthomolybdate, (NH 4) 2 MoO 4, and several other compounds.
Molybdic acid refers to hydrated forms of molybdenum trioxide and related species. The monohydrate (MoO 3 ·H 2 O) and the dihydrate (MoO 3 ·2H 2 O) are well characterized. They are yellow diamagnetic solids.
The trioxide, which is volatile at high temperatures, is the precursor to virtually all other Mo compounds as well as alloys. Molybdenum has several oxidation states, the most stable being +4 and +6 (bolded in the table at left). Molybdenum(VI) oxide is soluble in strong alkaline water, forming molybdates (MoO 4 2−).
The agriculture industry uses 500 tons per year as a fertilizer. In particular, its use has been suggested for treatment of whiptail in broccoli and cauliflower in molybdenum-deficient soils. [4] [5] However, care must be taken because at a level of 0.3 ppm sodium molybdate can cause copper deficiencies in animals, particularly cattle. [3]
A tube of commercial graphite powder lubricant with molybdenum disulfide additive (called "molybdenum") [33] Due to weak van der Waals interactions between the sheets of sulfide atoms, MoS 2 has a low coefficient of friction. MoS 2 in particle sizes in the range of 1–100 μm is a common dry lubricant. [34]
Vanadium pentoxide and molybdenum trioxide are the catalysts used for the benzene route, whereas vanadium phosphate is used for the butane route: [5] C 4 H 10 + 3.5 O 2 → C 4 H 2 O 3 + 4 H 2 O ∆H = −1236 kJ/mol. The main competing process entails full combustion of the butane, a conversion that is twice as exothermic as the partial oxidation.