What is the Difference Between Potassium Ferrocyanide and Potassium Ferricyanide?

The main difference between potassium ferrocyanide and potassium ferricyanide lies in the oxidation state of the iron ion present in each compound.

• Potassium Ferrocyanide: This compound has the chemical formula K4[Fe(CN)6]·3H2O and contains the ferrous ion (Fe^2+). It forms lemon-yellow monoclinic crystals and is considered a non-toxic compound. Potassium ferrocyanide is used as a fertilizer for plants, an identifying reagent for iron in labs, and as an anticaking agent for road salt and table salt.
• Potassium Ferricyanide: This compound has the chemical formula K3[Fe(CN)6] and contains the ferric ion (Fe^3+). It occurs as bright red crystals and has a low toxicity, but can be an irritant to eyes and skin. Potassium ferricyanide is used in various applications, such as an oxidant for catalyst regeneration in Sharpless dihydroxylations, in ferroxyl indicator solution for detecting metal oxidation, and in histology for detecting ferrous iron in biological tissue.

In summary, potassium ferrocyanide contains the ferrous ion (Fe^2+) and is a non-toxic compound, while potassium ferricyanide contains the ferric ion (Fe^3+) and has a low toxicity.

Comparative Table: Potassium Ferrocyanide vs Potassium Ferricyanide

The main difference between potassium ferrocyanide and potassium ferricyanide lies in the oxidation state of the iron ion in the compounds. Here is a comparison table highlighting the differences:

Potassium ferrocyanide is an inorganic compound with the chemical formula K4[Fe(CN)6].3H2O and occurs as monoclinic crystals with a lemon-yellow color. It contains the ferrous ion (Fe^2+) in a coordination complex with potassium and cyanide ions. On the other hand, potassium ferricyanide is an inorganic compound with the chemical formula K3[Fe(CN)6] and occurs as bright red crystals. It contains the ferric ion (Fe^3+) in a coordination complex with potassium and cyanide ions.