| Identification | More | [Name]
Molybdic acid | [CAS]
7782-91-4 | [Synonyms]
AMMONIUM DIMOLYBDATE
AMMONIUM MOLYBDATE
AMMONIUM MOLYBDATE (DI)
AMMONIUM MOLYBDATE REAGENT
AMMONIUM MOLYBDATE TS
AMMONIUM MOLYBDENUM OXIDE (DI)
diammonium dimolybdate
MOLYBDIC ACID
(beta-4)-molybdate(moo42-dihydrogen
dihydrogen,(T-4)-Molybdate
MOLYBDIC ACID, A.C.S. REAGENT
MOLYBDIC ACID CA. 85 % MOO3 (COMMER-CIAL QUALITY, CONTAINS AMMONIUM
MOLYBDIC ACID >=85.0% AS MOO3 A.C.S&
MolybdicAcid85%ExtraPure
MolybdicAcid>98%
MolybdicAcidAr
MolybdicAcid85%Gr
MolybdicAcidReagent
Molybdic acid, pract.
Molybdicacid,ACS,MoO385%min | [EINECS(EC#)]
231-970-5 | [Molecular Formula]
H2MoO4 | [MDL Number]
MFCD00010882 | [Molecular Weight]
161.95 | [MOL File]
7782-91-4.mol |
| Chemical Properties | Back Directory | [Definition]
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. | [Appearance]
white to slightly yellow powder | [Melting point ]
300 °C
| [density ]
3.1 g/mL at 25 °C(lit.) | [vapor density ]
6.2 (vs air) | [storage temp. ]
Store at +5°C to +30°C. | [solubility ]
slightly soluble in H2O; soluble in alkaline solutions | [form ]
white powder | [color ]
White powder | [Specific Gravity]
3.1 | [Odor]
Odorless | [PH]
3.46(1 mM solution);2.94(10 mM solution);2.43(100 mM solution) | [Water Solubility ]
70 g/l (20 ºC) | [Merck ]
13,6263 | [Exposure limits]
ACGIH: TWA 0.5 mg/m3
NIOSH: IDLH 1000 mg/m3 | [CAS DataBase Reference]
7782-91-4(CAS DataBase Reference) | [EPA Substance Registry System]
7782-91-4(EPA Substance) |
| Safety Data | Back Directory | [Hazard Codes ]
Xi | [Risk Statements ]
R36/37/38:Irritating to eyes, respiratory system and skin . | [Safety Statements ]
S24/25:Avoid contact with skin and eyes .
S22:Do not breathe dust . | [WGK Germany ]
3 | [TSCA ]
Yes | [HS Code ]
28111990 |
| Questions And Answer | Back Directory | [Descriptioin]
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.
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