A piece of iron wire weighing 1.63 g is converted to Fe²⁺(aq) and requires 21.9 mL of KMnO₄ solution for its titration.What is the molarity of the KMnO₄ solution? The reaction occurring during the titration is:
5 Fe²⁺(aq) + MnO₄^-(aq) + 8 H⁺(aq) → 5 Fe³⁺(aq) + Mn²⁺(aq) + 4 H₂O

Question

Quizplus · Accepted Answer

First, we need to calculate the moles of Fe in the wire:
molar mass of Fe = 55.85 g/mol
moles of Fe = 1.63 g / 55.85 g/mol = 0.0292 mol

From the balanced equation, we see that 1 mole of KMnO4 reacts with 5 moles of Fe. Therefore, the moles of KMnO4 used in the titration is:
moles of KMnO4 = 0.0292 mol / 5 = 0.00584 mol

Finally, we can calculate the molarity of the KMnO4 solution:
Molarity = moles of KMnO4 / volume of KMnO4 solution used
Molarity = 0.00584 mol / 0.0219 L = 0.2667 M, which rounds to 0.267 M.

A Piece of Iron Wire Weighing 1