Determination of iron by reaction

Question

Assignment:

Potassium permanganate, KMnO₄, is widely used as an oxidizing agent in volumetric analysis. In acid solution, MnO₄^- ion undergoes reduction to Mn²⁺ as shown in the following equation:

8 H⁺ (aq) + MnO­₄^- (aq) + 5 e^-  à Mn²⁺ (aq) + 4 H₂O

Since the MnO₄^- ion is violet and the Mn²⁺ ion is nearly colorless, the end point in titration using KMnO₃ as the tyrant can be taken as the first permanent pink color that appears in the solution.

KMnO₄ will be employed in this experiment to determine the percentage of iron in an unknown containing iron (II) ammonium sulfate, Fe (NH₄)₂(SO)₂ * 6 H₂O. The titration, which involves the oxidation of Fe²⁺ ion to Fe³⁺ by permanganate ion, is carried out in sulfuric acid solution to prevent the air oxidation of Fe²⁺. The end point of the titration is sharpened markedly if phosphoric acid is present, because Fe³⁺ ion produced in the titration forms an essentially colorless complex with the acid.

The number of moles of potassium permanganate used in the titration is equal to the product of the morality of the KMnO₄ and the volume used. The number of moles of iron present in the samples is obtained by weight of iron in the solid sample follows directly. 

Experiment:

Advance Study Assignment: Determination of iron by Reaction with Permanganate-A Redox Titration

Q1. Write the balanced net ionic equation for the reaction between Mn0₄ - ion and Fe²⁺ ion in acid solution.

Q2. How many moles of Fe²⁺ ion can be oxidized by 1.2 X l0^-2 moles Mn0₄^- ion in the reaction in Question 1?

Q3. A solid sample containing some Fe²⁺ ion weighs 1.750g. It requires 36.44 ml. 0.0244 M KMnO₄ to titrate the Fe²⁺ in the dissolved sample to a pink end point.

a.  How many moles Mn0₄ ion are required?

b.  How many moles Fe²⁺ are there in the sample?

c.  How many grams of iron are there in the sample?

d.  What is the percent Fe in the sample?

Q4. What is the percent Fe in iron (II) ammonium sulfate hexahydrate, Fe(NH₄ )₂(S0₄)2* 6 H₂O?

Provide complete and step by step solution for the question and show calculations and use formulas.