When combined iron
(III) and thiocyanate ions form Òblood redÓ complexes.
So in this experiment, spectrophotometric
methods will be used to determine the concentration of the iron (III) cyanato complex, [FeSCN 2+ ].
This however is difficult because the thiocyanate ion, SCN-, can react with the
ferric ion, Fe 3+, in acidic solutions to form a series of thiocyanato- complexes: Fe(SCN) 2+ , Fe(SCN)2+ , Fe(SCN)3, and Fe(SCN)4–.