Potassium chromate
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| Names | |
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| IUPAC name
Potassium chromate
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| Other names
Chromic acid, (K2CrO4), dipotassium salt
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| Identifiers | |
3D model (JSmol)
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| ECHA InfoCard | 100.029.218 |
| EC Number |
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PubChem CID
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| RTECS number |
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CompTox Dashboard (EPA)
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| Properties | |
| CrK2O4 | |
| Molar mass | 194.189 g·mol−1 |
| Appearance | Yellow odorless powder |
| Odor | odorless |
| Density | 2.7320 g/cm3 |
| Melting point | 968 °C (1,774 °F; 1,241 K) |
| Boiling point | 1,000 °C (1,830 °F; 1,270 K) |
| 62.9 g/100 mL (20 °C) 79.2 g/100 mL (100 °C) | |
| Solubility | insoluble in alcohol |
Refractive index (nD)
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1.74 |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Related compounds | |
Other anions
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Potassium dichromate Potassium molybdate Potassium tungstate |
Other cations
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Sodium chromate Calcium chromate Barium chromate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Potassium chromate (K2CrO4) is a yellow chemical indicator used for identifying concentrations of chloride ions in a salt solution with silver nitrate (AgNO3). It is a class two carcinogen and can cause cancer on inhalation.[1]
General information
Physical properties
Potassium Chromate is a lemon yellow compound that is in the form of a crystalline solid, and it is very stable.[citation needed]
Production
It is prepared by roasting powdered chromite with potash and limestone, treating the cinder with a hot potassium sulfate solution and leaching.
Alternatively, it may be prepared by the reaction of potassium dichromate and potassium hydroxide.
Reactions
When reacted with lead(II) nitrate, it creates an orange-yellow precipitate, lead(II) chromate. All ions hydrolyze in solution[citation needed].
Occurrence
Tarapacaite is the natural, mineral form of potassium chromate. It occurs very rarely and until now is known from only few localities on Atacama desert.[citation needed]
Safety
Potassium chromate is very toxic and may be fatal if swallowed. It may also act as a carcinogen, and can create reproductive defects if inhaled or swallowed. It also is a strong oxidizing agent if in the presence of H+ to produce the dichromate ion. It may react rapidly, or violently. It is also possible that it may react explosively with other reducing agents and flammable objects.
References
- ^ Potassium chromate information URL last accessed 15 March 2007
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