Names | |
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Other names
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Identifiers | |
3D model (JSmol) |
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Properties | |
K3CrO4 | |
Molar mass | 233.2886 g/mol |
Appearance | Green solid |
Melting point | 1,000 °C (1,830 °F; 1,270 K) (decomposes) |
Soluble, decomposes (25 °C)[1] | |
Structure | |
Similar to potassium hypomanganate | |
Thermochemistry | |
Std enthalpy of |
-370 ± 2 kcal mol−1[2] |
Hazards | |
Flash point | Not flammable |
Related compounds | |
Other anions |
Potassium hypomanganate |
Other cations |
Sodium hypochromate |
Related chromates |
Potassium chromate Potassium perchromate |
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 hypochromate is a chemical compound with the formula K3CrO4 with the unusual Cr5+ ion. This compound is unstable in water but stable in alkaline solution[1] and was found to have a similar crystal structure to potassium hypomanganate.[2]
This compound is commonly prepared by reacting chromium(III) oxide and potassium hydroxide at 850 °C under argon:[2]
This compound can be prepared other ways such as replacing chromium oxide with potassium chromate. It is important that there is no Fe2+ ions present because it would reduce the Cr(V) ions to Cr(III) ions.[1]
Potassium hypochromate decomposes in water to form chromium(III) oxide and potassium chromate when alkali is not present or low.[1] Potassium hypochromate also reacts with acids such as hydrochloric acid to form chromium(III) oxide, potassium chromate, and potassium chloride:[2]
Other reducing agents such as hydroperoxides can oxidize the hypochromate ion into chromate ions.[1] At extremely high temperatures, it decomposes into potassium chromate and potassium metal.[2]
This compound is used to synthesize various compounds such as chromyl chlorosulfate by reacting this compound with chlorosulfuric acid.[3]
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