What is ferroin?

Ferroin, also known as ferroin solution, is a complex of an iron (II) ion with the ligand 1,10-phenanthroline. It is often used as a redox indicator in chemistry experiments, particularly in titrations involving oxidation-reduction reactions.

Ferroin has a deep red color in its reduced form, which changes to a pale blue color when oxidized. This makes it useful in determining the endpoint of reactions involving redox titrations, as the color change is easily visible.

Ferroin is typically prepared by dissolving iron (II) sulfate and 1,10-phenanthroline in a solvent such as water or alcohol. The resulting solution can then be added to the reaction mixture to monitor the progress of the reaction.

Overall, ferroin is a versatile and widely used chemical reagent in analytical chemistry, particularly for determining the presence and concentration of reducing agents in solution.