GRADES: Tech/ EXTRA PURE / LR / AR / GR
Ammonium dichromate is the inorganic compound with the formula (NH4)2Cr2O7. In this compound, as in all chromates and dichromate’s, chromium is in a +6 oxidation state, commonly known as hexavalent chromium. It is a salt consisting of ammonium ions and dichromate ions. Ammonium dichromate is sometimes known as Vesuvian Fire, because of its use in demonstrations of tabletop “volcanoes”.
Molar mass: 252.07 g/mol
| Physical Properties | |
| Density | 2.115 g/cm3 |
| Melting point | 180 °C (356 °F; 453 K) decomposes |
| Solubility in water | 18.2 g/100ml (0 °C) 35.6 g/100ml (20 °C) 40 g/100ml (25 °C) 156 g/100ml (100 °C) |
| Solubility | insoluble in acetone soluble in alcohol |
| SPECIFICATION – AMMONIUM DICHROMATE | |||
| SR NO. | TEST | TECH | EXTRA PURE / LR |
| 1. | Description | Orange red crystals or crystalline powder | Orange red crystals or crystalline powder |
| 2. | Identity | Passes test | Passes test |
| 3. | Test Solution (10% w/v; water) | Bright and Clear | Bright and Clear |
| 4. | Assay [ (NH4)2Cr207] | 98% | 99.5% |
| 5. | Substances insoluble in water | 0.001% | 0.001% |
| 6. | Chloride ( Cl ) | 0.002% | 0.001% |
| 7. | Sulphate ( SO4) | 0.008% | 0.007% |
| 8. | Calcium (Ca) | 0.004% | 0.003% |
| 9. | Loss on drying ( 105° C) | 2.5% | 2.3% |
| SR NO. | TEST | AR/GR |
| 1. | Description | Orange red crystals or crystalline powder |
| 2. | Identity | Passes test |
| 3. | Test Solution (10% w/v; water) | The solution is clear and complete |
| 4. | Assay [ (NH4)2Cr207] | 99.7% |
| 5. | Substances insoluble in water | 0.001% |
| 6. | Chloride ( Cl ) | 0.0008% |
| 7. | Sulphate ( SO4) | 0.006% |
| 8. | Calcium (Ca) | 0.0007% |
| 9. | Potassium (K) | 0.07% |
| 10. | Sodium (Na) | 0.006% |
| 11. | Loss on drying ( 105° C) | 2% |
APPEARANCE:
Orange-Red Crystals
PROPERTIES:
At room temperature and pressure, the compound exists as orange, acidic crystals soluble in water and alcohol. It is formed by the action of chromic acid on ammonium hydroxide with subsequent crystallisation.
The (NH4)2Cr2O7 crystal (C2/c, z=4) contains a single type of ammonium ion, at sites of symmetry C1 (2, 3). Each NH4+ centre is surrounded irregularly by eight oxygen atoms at N-O distances ranging from ca. 2.83 to ca. 3.17 Å, typical of hydrogen bonds
USES / APPLICATIONS:
Used in pyrotechnics, in the early days of photography as well as in lithography, as a source of pure nitrogen in the laboratory, as a catalyst. It is also used as a mordant for dyeing pigments, in the manufacturing of alizarin, chrome alum, leather tanning and oil purification. The ammonium dichromate acts as the photoactive site.
PACKAGING:
Local – 50kg HDPE Bag with Airtight inside polylinner
Export- 50 kg fibre drums.