25.00 mL of distilled water was added to a beaker, along with 5.00 mL of 5.000 mM FeSO₄. The pH was adjusted using H₂SO₄ and measured with a Vernier pH Sensor. The solution was placed on a hot plate, the temperature was adjusted, and the reaction was initiated with the addition of 5.00 mL of 30.00 mM H₂O₂. After 10 minutes, the Vernier spectrophotometer was calibrated with the reaction mixture prior to adding SCN -, in order to eliminate the effects of absorption of extraneous species on the measurement. Then, 1.00 mL of 0.2000 M KSCN and 9.00 mL of the reaction mixture were added to a beaker. After mixing, they were placed in the spectrophotometer and the absorbance spectrum was obtained.