Question

A sample containing some iron (II) was titrated with 0.0241 M permanganate solution. The net volume of titrant required to complete the reaction was 11.2 mL. Question: How many moles of iron were in the sample?

Answer 1

Solution :-

Balanced redox equation is as follows

5Fe^2+(aq) + MnO4^-(aq) + 8H^+(aq)   --- > 5Fe^3+(aq) + Mn^2+(aq) +4H2O

Using the mole ratio of the permanganate and iron ion we can find the moles of iron (ll) ion

Moles = molarity x volume in liter

Moles of permanganate = 0.0241 mol per L * 0.0112 L

                                            = 0.00027 mol MnO4^-

(0.00027 mol MnO4^- * 5 mol Fe^2+ / 1 mol MnO4^- ) = 0.00135 mol Fe^2+

Therefore there are 0.00135 moles of iron in the solution.