Name | Molybdic acid |
Synonyms | Molybdic acid Molybdic(VI) acid Molybdic acid, for analysis MOLYBDIC ACID, A.C.S. REAGENT Molybdic acid, for analysis ACS Molybdate (MoO42-), dihydrogen, (T-4)- Molybdate (MoO42-), dihydrogen, (beta-4)- hydroxy-(hydroxy-dioxo-molybdenio)oxy-dioxo-molybdenum |
CAS | 7782-91-4 |
EINECS | 231-970-5 |
InChI | InChI=1/2Mo.2H2O.5O/h;;2*1H2;;;;;/q2*+1;;;;;;;/p-2/rH2Mo2O7/c3-1(4,5)9-2(6,7)8/h3,6H |
Molecular Formula | HMoO4- |
Molar Mass | 160.95 |
Density | 3.1 g/mL at 25 °C (lit.) |
Melting Point | 300 °C |
Water Solubility | 70 g/l (20 ºC) |
Solubility | Soluble in ammonia, sulfuric acid and fixed lye, slightly soluble in water. |
Vapor Density | 6.2 (vs air) |
Appearance | White powder |
Specific Gravity | 3.1 |
Color | White powder |
Odor | Odorless |
Exposure Limit | ACGIH: TWA 0.5 mg/m3NIOSH: IDLH 1000 mg/m3 |
Merck | 13,6263 |
PH | 3.46(1 mM solution);2.94(10 mM solution);2.43(100 mM solution) |
Storage Condition | Store at +5°C to +30°C. |
Sensitive | Easily absorbing moisture |
MDL | MFCD00036287 |
Physical and Chemical Properties | Yellow monoclinic crystal or powder. Industrial products generally contain some ammonium molybdate. |
Use | Used in medicine, metal plating coloring, pigment, petroleum catalyst |
Risk Codes | R36/37/38 - Irritating to eyes, respiratory system and skin. R48/20/22 - R36/37 - Irritating to eyes and respiratory system. |
Safety Description | S24/25 - Avoid contact with skin and eyes. S22 - Do not breathe dust. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
WGK Germany | 3 |
TSCA | Yes |
HS Code | 28111990 |
A yellow monoclinic crystal or powder. Industrial products generally contain some ammonium molybdate. The relative density was 3. 124. One molecule of crystal water was lost by heating to 70 °c. Slightly soluble in water, soluble in alkali solution or alkali metal carbonate.
ammonium molybdate nitric acid neutralization method: The Molybdenite is crushed to 60~80 mesh, in the baking furnace at 500~550 ℃ for 6~8H, leaching with ammonia to obtain ammonium molybdate solution, after purification and removal of impurities, it is acidified with nitric acid to precipitate molybdic acid precipitate, washed with warm water, centrifuged, dehydrated, dried and pulverized to obtain a finished molybdic acid product.
used as a raw material for producing a molybdenum-based catalyst and a molybdenum salt. It can also be used in medicine, metal plating colorants, blue pigment of ceramic glaze, oil painting and watercolour pigment, paint, etc.
A fiber barrel packed with a clean polyethylene plastic bag lined with 25kg per barrel. Pay attention to prevent the plastic bag mouth crack. Store in a cool, ventilated, dry warehouse, pay attention to moisture. In case of humid air, the powder is easy to absorb moisture and must be sieved. Tie the mouth of the bag tightly or cover tightly to avoid adhesion. When transporting, cover material shall be provided to prevent rain and sun exposure, and shall not be stored and transported together with strong acids and alkalis. When loading and unloading should be light to prevent packaging damage. In case of fire, it can be suppressed by water, sand and all kinds of fire extinguishing.
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Use | molybdic acid is used as a precursor for the production of ammonium molybdate tetrahydrate and molybdenum (IV) sulfide, its mixture in concentrated sulfuric acid is called Freund's reagent and is used in analytical chemistry for the detection of alkaloids. used in medicine, metal plating coloring, pigment, petroleum catalyst, etc. used as a raw material for producing molybdenum-based catalysts and molybdenum salts. It can also be used in medicine, metal plating colorants, blue pigment of ceramic glaze, oil painting and watercolour pigment, paint, etc. used as analytical reagents and also in the electronics industry for the determination of phosphorus, phosphate and lead. Ceramic glaze. |
preparation | 1. Molybdate was crushed to 60~80 mesh by ammonium molybdate neutralization with nitric acid, and then oxidized and roasted in a baking furnace at 500~550 ℃ for 6~8H, then leached with ammonia to obtain ammonium molybdate solution, after purification and removal of impurities, it is acidified with nitric acid to precipitate molybdic acid precipitate, washed with warm water, centrifuged, dehydrated, dried and pulverized to obtain a finished molybdic acid product. 2. The hydrochloric acid solution of molybdenum trioxide MoO3 is heated at 40~60 ℃ to obtain molybdic acid H2MoO4. In addition, a monohydrate can be obtained by adding concentrated nitric acid to an aqueous solution of ammonium heptamolybdate tetrahydrate (secondary ammonium molybdate)(NH4) 6mo7o24 · 4H2O. 3. Molybdenum can be dissolved in AgNO3 solution, precipitation of molybdic acid and silver, the reaction can be carried out quantitatively. 4. Add about 15% ammonium molybdate solution to the same volume of nitric acid solution (relative density 1.16), then add a certain amount of ammonium nitrate and a small amount of molybdate Crystal (as a seed crystal), stir evenly, let stand until the crystallization is complete: the precipitate obtained by filtration is washed with ice water until it is qualified, and dried after Suction filtration, that is, anhydrous molybdic acid. 5. Add concentrated HNO3 to the aqueous solution of ammonium secondary molybdate to make the pH of the solution less than 1, or add sulfuric acid to barium secondary molybdate. |
production method | molybdenite was crushed to 60~80 mesh by ammonium molybdate nitric acid neutralization method, in the baking furnace at 500~550 ℃ for 6~8H, leaching with ammonia to obtain ammonium molybdate solution, after purification to remove impurities, with nitric acid acidification, precipitation of molybdate, washing with warm water, centrifugal dehydration, drying, grinding, molybdic acid product. MoS2 3.5O2 → MoO3? 2SO2MoO3 2NH4OH →(NH4)2MoO4 H2O(NH4)2MoO4 2HNO3 H2O → H2MoO4? H2O 2NH4NO3 |