Production
Prussian blue is produced by oxidation of ferrous ferrocyanide salts. These white solids have the formula M2Fe where M+ = Na+ or K+. The iron in this material is all ferrous, hence the absence of deep color associated with the mixed valency. Oxidation of this white solid with hydrogen peroxide or sodium chlorate produces ferricyanide and affords Prussian Blue.
A "soluble" form of PB, K, which is really colloidal, can be made from potassium ferrocyanide and iron(III):
- K+ + Fe3+ + 4- → KFeIII
The similar reaction of potassium ferricyanide and iron(II) results in the same colloidal solution, because 3- is converted into ferrocyanide.
"Insoluble" Prussian blue is produced if in the reactions above an excess of Fe3+ or Fe2+, respectively, is added. In the first case:
- 4Fe3+ + 34- → FeIII3
Read more about this topic: Prussian Blue
Famous quotes containing the word production:
“[T]he asphaltum contains an exactly requisite amount of sulphides for production of rubber tires. This brown material also contains “ichthyol,” a medicinal preparation used externally, in Webster’s clarifying phrase, “as an alterant and discutient.””
—State of Utah, U.S. public relief program (1935-1943)
“The development of civilization and industry in general has always shown itself so active in the destruction of forests that everything that has been done for their conservation and production is completely insignificant in comparison.”
—Karl Marx (1818–1883)
“It is part of the educator’s responsibility to see equally to two things: First, that the problem grows out of the conditions of the experience being had in the present, and that it is within the range of the capacity of students; and, secondly, that it is such that it arouses in the learner an active quest for information and for production of new ideas. The new facts and new ideas thus obtained become the ground for further experiences in which new problems are presented.”
—John Dewey (1859–1952)