This graph had a peak at approximately 450 nm, which is consistent with the peak observed during the determination of the ferric thiocyanate standard calibration curve. As stated before, the spectrophotometer was calibrated with the reaction mixture which eliminates absorbance readings of substances. Thus, by mixing the KSCN with the reaction mixture and measuring the absorbance of the new solution, the spectrum would only correspond to the absorbance of newly produced species. The peak at approximately 450 nm demonstrates that FeSCN 2+ was being produced and the oxidation of iron(II) through the Fenton Process was occurring, since iron(III) ions were available to complex with thiocyanate ions.