Formula K3CrO8 | Appearance red brown | |
 | ||
How to make potassium tetraperoxochromate v
Potassium peroxochromate, or potassium tetraperoxochromate(V), is an inorganic chemical having the chemical formula K3[Cr(O2)4]. A crystalline ionic solid with a brown color, it is the potassium salt of tetraperoxochromate(V), one of the few examples of chromium in the +5 oxidation state.
Contents
Preparation
Potassium peroxochromate is prepared by reacting hydrogen peroxide with potassium chromate at low temperatures:
2 CrO2−4 + 8 H
2O
2 → 2 [Cr(O
2)
4]2−
+ 8 H
2O
The intermediate tetraperoxochromate(VI) is reduced by hydrogen peroxide, forming tetraperoxochromate(V):
2 [Cr(O2)
4]2−
+ 2 OH−
+ H
2O
2 → 2 [Cr(O
2)
4]3−
+ 2 H
2O + O
2
Thus, the overall reaction is:
2 CrO2−4 + 9 H
2O
2 + 2 OH−
→ 2 [Cr(O
2)
4]3−
+ 10 H
2O + O
2
The compound decomposes spontaneously at higher temperatures.
References
Potassium tetraperoxochromate(V) Wikipedia(Text) CC BY-SA