Oxidation – Reduction Titration: Determination of Iron (II)
Abstract:
The purpose of this experiment was to determine the percentage purity of the iron(II) salt in an unknown sample. We performed titrations using Potassium permanganate which is a strong oxidizing agent, with unknown sample dissolved in deionized water. The result of the experiment was a 99.5% purity for the anhydrous iron (II) ammonium sulfate.
Introduction: In this experiment, oxidation/reduction (or redox) will be used in the titration analysis of an iron compound. We will use potassium permanganate, KMnO4, as the titrant in the analysis of an unknown sample containing iron to determine the percent iron by mass in the sample. In acidic solution, potassium permanganate rapidly and quantitively oxidizes iron(II) to iron (III), while itself being reduced to manganese(II). (2) The half reactions for the process are:
MnO4+8H + 5e→Mn2++4H2O reduction
Fe2+ → Fe3+ + e− Oxidation
When these half reaction are combined to give the overall balanced chemical reaction equation, a factor of five must be used with the iron half-reaction so that the number of electrons lost in the overall oxidation will equal the number of electrons gained in the reduction: MnO4+8H + Fe2+ →Mn2++4H2O + 5Fe3
Potassium permanganate is one of the most commonly used oxidizing agents because it is extremely powerful, inexpensive and ready available. (1) it does have some drawbacks however. Because KMnO4 is a strong oxidizing agent, it reacts with practically anything that can be oxidized. This tends to make solutions of KMnO4, difficult to store without it decomposing or changing in concentration. Because of this limitation, it is common to prepare a standardized, (3) and then use KMnO4 solutions for analysis all on the same day. It is not possible to prepare a KMnO4 standard solution based on a mass: Solid potassium permanganate cannot be obtained in a completely pure state due to the high
The purpose of this experiment was to determine the percentage purity of the iron(II) salt in an unknown sample. We performed titrations using Potassium permanganate which is a strong oxidizing agent, with unknown sample dissolved in deionized water. The result of the experiment was a 99.5% purity for the anhydrous iron (II) ammonium sulfate.
Introduction: In this experiment, oxidation/reduction (or redox) will be used in the titration analysis of an iron compound. We will use potassium permanganate, KMnO4, as the titrant in the analysis of an unknown sample containing iron to determine the percent iron by mass in the sample. In acidic solution, potassium permanganate rapidly and quantitively oxidizes iron(II) to iron (III), while itself being reduced to manganese(II). (2) The half reactions for the process are:
MnO4+8H + 5e→Mn2++4H2O reduction
Fe2+ → Fe3+ + e− Oxidation
When these half reaction are combined to give the overall balanced chemical reaction equation, a factor of five must be used with the iron half-reaction so that the number of electrons lost in the overall oxidation will equal the number of electrons gained in the reduction: MnO4+8H + Fe2+ →Mn2++4H2O + 5Fe3
Potassium permanganate is one of the most commonly used oxidizing agents because it is extremely powerful, inexpensive and ready available. (1) it does have some drawbacks however. Because KMnO4 is a strong oxidizing agent, it reacts with practically anything that can be oxidized. This tends to make solutions of KMnO4, difficult to store without it decomposing or changing in concentration. Because of this limitation, it is common to prepare a standardized, (3) and then use KMnO4 solutions for analysis all on the same day. It is not possible to prepare a KMnO4 standard solution based on a mass: Solid potassium permanganate cannot be obtained in a completely pure state due to the high