The result is an strong red mixture with an ion as shown [Fe(SCN)(H2O)5]2+ 5. The reaction of this two mixtures is shown in figure 15. This causes an imbalance and forces the reaction to move to the right, as indicated [Fe(SCN)6)3-. 6. The addition of potassium persulfate (K2S2O8), to this solution acts as an oxidising agent which reduces the reactants by pushing the energy to the left that way the balance is equal in both sides 7. The result of this reaction is shown below in figure 26. The aim of this experiment was to determine the amount of iron in a breakfast cereal such as, Nutri -grain through the use of a series of calibrated standards measured using a spectrometer. The final concentration results were then compared to the reference value to investigate if the method used to analyse the iron quantity was …show more content…
The dish was then placed into a furnace at a heat of 550 °C for 1 hour. After it has been ashed it was transferred to a 100mL conical flask and 2ml of concentrated HNO3 and 2ml of concentrated HCL was added to the flask. It was left for 5minutes. 5ml of deionised water was added while swirling then it was boiled for 10-15 minutes. 3M HCL was added every once in a while, the rest was filtered using a filtering paper. It was diluted with 10ml of water and transferred into a clean and dry sample bottle. The residual was washed and it was transferred to the sample bottle. Any left overs in the flask was filtered into the bottle. 30mg L Fe3+ prepared was pipetted into 6 50mL volumetric flasks. Each flask contained 30ml of 0.5M KSCN, 3.3ml of 3M nitric acid (HNO3), 5ml of 0.2M of a oxidate which was potassium persulfate (K2S2O8) and 5ml of 30mg Analyte which was iron (Fe3+). Then deionised water was used to fill it up to the mark. The flask was mixed and left for 15 minutes to equilibrate. Another 50ml volumetric flask was used as a blank containing all of the reagents except the analyte (Fe3+). Then deionised water was used up to the mark, the flask was mixed and left for 15minutes to equilibrate. The Iron sample from the cereal was transferred into a volumetric flask and 60mL of 0.5M KSCN and 5mL K2S208 was added and marked with deionised water then mixed and left to equilibrate for 15minutes. After the