Magnesium chromate - inorganic compound, magnesium salt and chromic acid with the formula MgCrO 4 , yellow crystals, soluble in water, forms crystalline hydrates .
| Magnesium Chromate | |
|---|---|
| Are common | |
| Systematic name | Magnesium Chromate |
| Traditional names | Magnesium Chromium |
| Chem. formula | MgCrO 4 |
| Physical properties | |
| condition | yellow crystals |
| Molar mass | 140.30 g / mol |
| Density | hydrate - 1,695 g / cm³ |
| Thermal properties | |
| T. | 525-645 ° C |
| Chemical properties | |
| Water solubility | 32.06 0 ; 54.8 25 g / 100 ml |
| Classification | |
| Reg. CAS number | 13423-61-5 |
| Reg. EINECS number | |
| Security | |
| MPC | 0.01 mg / m³ |
Content
Getting
- Heating a mixture of calcium chromate and magnesium sulphate :
Physical Properties
Magnesium chromate forms crystals of the orthorhombic system , space group C mcm , cell parameters a = 0.5497 nm, b = 0.8368 nm, c = 0.6147 nm [1] .
As the temperature rises, a transition occurs to the monoclinic phase, the space group is C 2 / m , the cell parameters are a = 0.995 nm, b = 0.916 nm, c = 0.6759 nm, β = 103.68 °, Z = 4.
Soluble in water.
Forms crystalline hydrates of the composition MgCrO 4 • n H 2 O, where n = 1, 5, 7 and 11.
MgCrO 4 • 7H 2 O crystallohydrate — rhombic syngony yellow crystals, space group P 2 1 2 1 2 1 , cell parameters a = 1,189 nm, b = 1,201 nm, c = 0.689 nm, Z = 4.
Chemical Properties
- Decomposes when heated:
Application
- Used for the manufacture of refractory lining of metallurgical furnaces.
Notes
- ↑ Muller O., White WB, Roy R. X-ray diffraction study // Zeitschrift fuer Kristallographie, Kristallgeometrie, Kristallphysik, Kristallchemie. - 1969. - T. 130 . - pp . 112-120 .
Literature
- Chemist Handbook / Redkol .: Nikolsky B.P. et al. - 2nd ed., Rev. - M.-L.: Chemistry, 1966. - T. 1. - 1072 p.
- Chemist Handbook / Redkol .: Nikolsky B.P. et al. - 3rd ed., Rev. - L .: Chemistry, 1971. - T. 2. - 1168 p.
- CRC Handbook of Chemistry and Physics . - 89th edition. - Taylor and Francis Group, LLC, 2008-2009.
- Chemical Encyclopedic Dictionary / Redkol .: Knunyants I.L. et al. - M .: Soviet Encyclopedia, 1983. - 792 p.
- Richard C. Ropp ,. Encyclopedia of the Alkaline Earth Compounds . - Elsevier, 2013. - ISBN 978-0-444-59550-8 .