Na4[Fe(CN)6] is a chemical compound known as sodium ferrocyanide. It consists of four sodium ions (Na⁺) and one ferrocyanide ion ([Fe(CN)6]⁴⁻). The ferrocyanide ion contains one iron (Fe) atom surrounded by six cyanide (CN) groups, which are coordinated to the iron. This compound is often used in various applications, including as a food additive and in the production of pigments. Sodium ferrocyanide is also utilized in the laboratory for its properties in complexation and as a reagent in analytical chemistry, particularly in the detection of certain metals.