Potassium ferrioxalate

Potassium ferrioxalate, also known as potassium tris(oxalato)ferrate(III), is a chemical compound with the formula K₃[Fe(C₂O₄)₃]. It is a salt consisting of potassium ions and the complex ion [Fe(C₂O₄)₃]³⁻. This compound is an example of a coordination complex, where a central iron(III) ion is surrounded by three oxalate ions acting as ligands. Potassium ferrioxalate is notable for its use in the study of photochemistry, serving as a standard chemical for measuring the intensity of light.

Properties

Potassium ferrioxalate forms green crystals that are soluble in water. The solubility in water is an important property that allows it to be used in various chemical reactions and processes. When dissolved, it forms a green solution due to the presence of the [Fe(C₂O₄)₃]³⁻ ions, which are responsible for the color. The compound is sensitive to light, which can cause it to decompose, releasing carbon dioxide and forming iron(II) compounds.

Synthesis

The synthesis of potassium ferrioxalate involves the reaction of iron(III) chloride with potassium oxalate in the presence of oxalic acid. This process typically requires careful control of the reaction conditions, including temperature and pH, to ensure the formation of the desired product. The reaction can be represented by the following equation:

\[ \text{FeCl}_3 + 3\text{K}_2\text{C}_2\text{O}_4 + 3\text{H}_2\text{C}_2\text{O}_4 \rightarrow \text{K}_3[\text{Fe}(\text{C}_2\text{O}_4)_3] + 3\text{KCl} + 6\text{H}_2\text{O} \]

Applications

Potassium ferrioxalate is primarily used in the field of photochemistry. It acts as a photosensitizer in the study of chemical reactions that are initiated by the absorption of light. This property makes it a valuable tool for understanding the mechanisms of photochemical processes. Additionally, it has been used in the calibration of photometers, devices that measure the intensity of light, due to its consistent and predictable response to light exposure.

Safety

Handling potassium ferrioxalate requires caution as it is considered a mild irritant and can be harmful if ingested or if it comes into contact with skin and eyes. Appropriate safety measures, including the use of gloves and eye protection, are recommended when working with this compound.

See Also

• Coordination complex
• Photochemistry
• Oxalate
• Iron compounds