MOLYBDIC ACID

Molybdic Acid

CAS Number = 7782-91-4
EC Number = 231-970-5
IUPAC Name = dihydroxy(dioxo)molybdenum
Chemical Formula = MoO3·H2O

Chemical and Physical Properties

Property Name                            Property Value
Molecular Weight                        161.96 
Hydrogen Bond Donor Count                2
Hydrogen Bond Acceptor Count            4
Rotatable Bond Count                    0
Exact Mass                                163.900712
Monoisotopic Mass                        163.900712
Topological Polar Surface Area            74.6 Ų
Heavy Atom Count                        5
Formal Charge                            0
Complexity                                81.3
Isotope Atom Count                        0
Defined Atom Stereocenter Count            0
Undefined Atom Stereocenter Count        0
Defined Bond Stereocenter Count            0
Undefined Bond Stereocenter Count        0
Covalently-Bonded Unit Count            1
Compound Is Canonicalized                Yes

Molar mass                                161.95 g mol−1
Appearance                                white crystals (anhydrous)
                                        yellow crystals (monohydrate)
Density                                    3.112 g/cm3 (anhydrous)
                                        3.124 g/cm3 (monohydrate)
Melting point                            300 °C (572 °F; 573 K)[1]
Solubility in water                        1510 mg dm−3 Soluble in 10% ammonia 35gm/lt

Molybdic acid refers to hydrated forms of molybdenum trioxide and related species.
The monohydrate (MoO3·H2O) and the dihydrate (MoO3·2H2O) are well characterized.
They are yellow diamagnetic solids.

Molybdic Acid is generally immediately available in most volumes.
High purity, submicron and nanopowder forms may be considered.
American Elements produces to many standard grades when applicable, including Mil Spec (military grade); ACS, Reagent and Technical Grade; Food, Agricultural and Pharmaceutical Grade; Optical Grade, USP and EP/BP (European Pharmacopoeia/British Pharmacopoeia) and follows applicable ASTM testing standards.
Typical and custom packaging is available.
Additional technical, research and safety (MSDS) information is available as is a Reference Calculator for converting relevant units of measurement.

Molybdic acid refers to hydrated forms of molybdenum trioxide.
There is no information related to the biological and pharmacological application of molybdic acid.
It is known, that this substance is used as heterogeneous catalysts.

Molybdic acid and its salts are used to make the Froehde reagent for the presumptive identification of alkaloids.

Molybdic Acid is the hydrated forms of molybdenum trioxide.
It is used for the determination of phosphorus or phosphate and lead.
It is also used in glazes for ceramics, in manufacturing of Rock Phosphate based Fertilizers, Pigments, Dyes, Colors etc.

The simplest form, the monohydrate, is MoO3.H2O, the dihydrate MoO3.2H2O is also known.
The solid state structure of MoO3.H2O consists of layers of octahedrally coordinated MoO5(H2O) units where 4 vertices are shared.
the dihydrate has the same layer structure with the extra H2O molecule intercalated between the layers.

The salts of molybdic acid are called molybdates.

According to a comparative study of the literature, supplemented by well-aimed experimental investigations and equilibrium calculations, the terms 'molybdic acid' or 'polymolybdic acid', used for many substances, species, or solutions in the literature, are applicable to a species, a solution, and two solids: a) The monomeric molybdic acid, most probably having the formula MoO2(OH)2(H2O)2 (= H2MoO4, aq), exists in (aqueous) solution only and never exceeds a concentration of ∼ 10-3 M since at higher concentrations it reacts with other monomeric molybdenum(VI) species to give anionic or cationic polymers.
b) A concentrated (> 0.1 M MoVI) aqueous molybdate solution of degree of acidification P = 2 (realized, e.g., by a solution of one of the MoVI oxides; by any molybdate solutions whose cations have been exchanged by H2O+ on a cation exchanger; by suitable acidification of a molybdate solution) contains 8 H3O+ and the well-known polyanion Mo36O112(H2O)168-exactly in the stoichiometric proportions.
c) A glassy substance, obtained from an alkali metal salt-free solution prepared acording to (b), refers to the compound (H3O)8[Mo36O112(H2O)16] · xH2O, x = 25 - 29.
d) A solid having the ideal composition [(H3O)Mo5O15(OH)H2O · H2O]∞ consists of a polymolybdate skeleton (the well-known 'decamolybdate' structure), in the tunnels of which H3O+ and H2O are intercalated.
The structure is very unstable if only H3O+ cations are present, but it is enormously stabilized by a partial exchange of H3O+ by certain alkali or alkaline earth metal cations.
For the compounds MoO3, MoO3·H2O, and MoO3 · 2 H2O the term 'molybdic acid' is unjustified.
The commercial product 'molybdic acid, ∼ 85% MoO3' is the well-known polymolybdate (NH4)2O · 4 MoO3 with a layer structure of the polyanion.

Molybdic Acid Sodium Salt Dihydrate, ACS Grade is a molybdate source useful in fertilizers.
It is also an inhibitor of a variety of receptors and a stabilizer of progesterone and androgen receptors.
Molybdic acid sodium salt has been shown to reversibly inhibit estrogen receptor activation.

The monohydrate is a yellow solid consisting of monoclinic crystals; density 3.124 g/cm3 at 15°C; loses water of crystallization on heating at 70°C;
sparingly soluble in cold water (1.33 g/L at 18°C); moderately soluble in hot water 25.68 g/L at 70°C; soluble in caustic soda and sodium carbonate solution.
The anhydrous acid consists of white hexagonal crystals; density 3.112 g/cm3; converts to molybdenum trioxide, MoO3 at 70°C; slightly soluble in water; soluble in alkalies and sulfuric acid.
The monohydrate is prepared by treating a molybdate solution with nitric acid, followed by crystallization which may take several weeks to separate out as a yellow solid.
The anhydrous molybdic acid is obtained as a white crystalline substance by careful dehydration of the yellow monohydrate.

Molybdic acid of commerce iseither ammonium molybdate (molybdic acid 85%)or molybdenum trioxide.
The use of the term inter-changeably for these compounds has caused con-fusion.
Solutions of molybdic acid are very com-plex chemically since they show a great tendencyto polymerize.

Molybdic acid is the hydrated form of molybdenum trioxide.
It is also known as molybdenum hydroxide oxide, molybdic(VI) acid, dihydrogentetraoxomolybdate.
It is a yellow diamagnetic solid.
The property value of hydrogen bond donor and hydrogen bond acceptor are 2 and 4 respectively.

Molybdic Acid (85%*) is a white, crystalline powder, only slightly soluble in water until the addition of Ammonium Hydroxide which significantly increases the solubility.
It is a high purity compound.
The designation "(85%)" refers to the minimum MoO3 content in the product.

Molybdic Acid (85%) can be made by the thermal dehydration of Ammonium Heptamolybdate (NH4)6Mo7O24·4H2O.
The Molybdenum Trioxide (MoO3) analysis of the typical product, 86-88%, suggests the formula (NH4)6Mo7O24, which contained 86.6% MoO3.
The formula listed by CAS corresponding to the CAS Number is H2MoO4.
However, this is inconsistent with the American Chemical Society Specifications for the product.
“Reagent Chemicals”, Eighth Ed., American Chemical Society, Washington, D.C.
1993 states that Molybdic Acid (85%) “consists largely of Ammonium Molybdate”.
Ammonium Heptamolybdate Anhydride is consistent.
Molybdic Acid (85%) is not soluble in water as is Ammonium Heptamolybdate, but like Molybdenum Trioxide, it is soluble in dilute Ammonium Hydroxide.

Molybdic Acid, 85 Percent, Reagent, ACS is a solid and the hydrated form of molybdenum trioxide.
Molybdic acid salts are called molybdates.
The most simple of the solid form is call the monohydrate.
As an ACS grade quality reagent, its chemical specifications are the de facto standards for chemicals used in many high-purity applications and typically designate the highest quality chemical available for laboratory use.
Spectrum Chemical manufactured Reagent ACS grade products meet the toughest regulatory standards for quality and purity.

A parent acid of molybdates; specifically either of two hydrated forms of molybdenum trioxide, H₂ MoO₄ and H₄ MoO₅, obtained from acid solutions of molybdates.

Molybdic acid
Molybdic acid refers to solid, hydrated forms of molybdenum trioxide and species in aqueous solution.
The simplest solid form, the monohydrate, is MoO3·H2O, though the dihydrate is also known.
The solid state structure of MoO3·H2O consists of layers of octahedrally coordinated MoO5· units where 4 vertices are shared.
The dihydrate has the same layer structure with the extra H2O molecule intercalated between the layers.
In aqueous solutions of acidified molybdate salts low concentration molecular O3Mo·3H2O has been characterised spectroscopically.
The salts of molybdic acid are called molybdates.

Structure of Molybdic Acid
Solid forms of molybdic acid are coordination polymers.
The monohydrate MoO3·H2O consists of layers of octahedrally coordinated MoO5·(H2O) units where 4 vertices are shared.The dihydrate (image shown above) has the same layer structure with the "extra" H2O molecule intercalated between the layers.

Structure of molybdic acid in solution
In acidified aqueous solutions of molybdic acid, the complex MoO3(H2O)3 is observed.
Once again, molybdenum adopts octahedral molecular geometry, probably with three oxo ligands and three aquo ligands.

The salts of molybdic acid are called molybdates.
They arise by adding base to solutions of molybdic acid.

Applications
Many molybdenum oxides are used as heterogeneous catalysts, e.g.
for oxidations.
Molybdic acid and its salts are used to make the Froehde reagent for the presumptive identification of alkaloids.

Molybdic Acid Disodium Salt Dihydrate has displayed the ability to stabilize both the androgen and progesterone receptor.

Applications
Molybdic acid is used as a precursor in the production of ammonium molybdate tetrahydrate and molybdenum(IV) sulfide.
The mixture of molybdic acid in concentrated sulfuric acid is called as Froehde reagent, which finds application in analytical chemistry for the detection of alkaloids.

APPLICATION
M 2335 (OTTO) Molybdic acid, 85% Cas 7782-91-4 - used as a precursor in the production of ammonium molybdate tetrahydrate and molybdenum(IV) sulfide.
The mixture of molybdic acid in concentrated sulfuric acid is called as Froehde reagent, which finds application in analytical chemistry for the detection of alkaloids.

Preparation Method
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.

Chemical Properties
white crystals or crystalline powder

FIRST AID MEASURES
General advice
Consult a physician.
Show this safety data sheet to the doctor in attendance.Move out of dangerous area.

If inhaled
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.

In case of skin contact
Wash off with soap and plenty of water.
Consult a physician.

In case of eye contact
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.

If swallowed
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.

FIREFIGHTING MEASURES
Conditions of flammability
Not flammable or combustible.
Suitable extinguishing media
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special protective equipment for firefighters
Wear self contained breathing apparatus for fire fighting if necessary.
Hazardous combustion products
Hazardous decomposition products formed under fire conditions.
- Nature of decomposition products not known.

HANDLING AND STORAGE
Precautions for safe handling
Avoid contact with skin and eyes.
Avoid formation of dust and aerosols.
Provide appropriate exhaust ventilation at places where dust is formed.

Conditions for safe storage
Keep container tightly closed in a dry and well-ventilated place.

Personal protective equipment
Respiratory protection
For nuisance exposures use type P95 (US) or type P1 (EU EN 143) particle respirator.For higher level protection
use type OV/AG/P99 (US) or type ABEK-P2 (EU EN 143) respirator cartridges.
Use respirators and components
tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Hand protection
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove removal technique (without touching
glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in
accordance with applicable laws and good laboratory practices.
Wash and dry hands.

Immersion protection
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: > 480 min
Material tested:Dermatril® (Aldrich Z677272, Size M)

Splash protection
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: > 30 min
Material tested:Dermatril® (Aldrich Z677272, Size M)
data source: KCL GmbH, D-36124 Eichenzell, phone +49 (0)6659 873000, e-mail sales@kcl.de, test method:
EN374
If used in solution, or mixed with other substances, and under conditions which differ from EN 374, contact the
supplier of the CE approved gloves.
This recommendation is advisory only and must be evaluated by an Industrial
Hygienist familiar with the specific situation of anticipated use by our customers.
It should not be construed as
offering an approval for any specific use scenario.

Eye protection
Safety glasses with side-shields conforming to EN166 Use equipment for eye protection tested and approved under
appropriate government standards such as NIOSH (US) or EN 166(EU).

Skin and body protection
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the
concentration and amount of the dangerous substance at the specific workplace.

Hygiene measures
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of
workday.

STABILITY AND REACTIVITY
Chemical stability
Stable under recommended storage conditions.
Possibility of hazardous reactions
no data available
Conditions to avoid
no data available
Materials to avoid
Strong bases, Strong oxidizing agents
Hazardous decomposition products
Hazardous decomposition products formed under fire conditions.
- Nature of decomposition products not known.
Other decomposition products - no data available

Synonyms

molybdic acid
molybdic(VI) acid
Molybdic acid
7782-91-4
dihydroxy(dioxo)molybdenum
Molybdic(VI) acid
Molybdicacid
UNII-I96N991J1N
H2MoO4
MFCD00036287
H2MoO4.12H2O
I96N991J1N
11099-00-6
Molybdate (MoO42-), dihydrogen, (T-4)-
Molybdic Acid ACS
EINECS 231-970-5
Diammonium dimolybdate
Ammonium molybdenum oxide ((NH4)2Mo2O7)
dihydroxidodioxidomolybdenum
Molybdate (MoO42-), hydrogen (1:2), (T-4)-
[MoO2(OH)2]
Molybdic acid, LR, >=85%
CHEBI:25371
Molybdate (Mo2O72-), diammonium
EINECS 248-517-2
AKOS005110999
FT-0628968
Molybdic acid, p.a., ACS reagent, 85.0%
Molybdate (MoO42-), dihydrogen, (beta-4)-
C06232
EC 248-517-2
Q412950
Molybdic acid, >=85.0% MoO3 basis, ACS reagent