Question

Redox Tiration of Hydrogen Peroxide

2. The potassium permanganate in this reaction can be first standardured by titrating with
ferrous ammonium sulfate hexahydrate (H.) Fe(50.) H.O, molar mass 392.2 g/mol) in
the following reaction: MnO,+ 5Fe + 8H-Me + 5 + 4H₂O


1.0092 g of the iron salt is titrated with potassium permanganate, requiring 25.11 ml of solution to reach equivalence. What is the molarity of the permanganate solution?

Answer 1

To find the molarity of the potassium permanganate solution, calculate the moles of iron and then use the volume of the permanganate solution to find its molarity. The molarity of the permanganate solution 0.0205 M.

Step-by-step explanation:

To find the molarity of the potassium permanganate solution, we need to use the balanced equation for the titration reaction:

MnO₄⁻ + 5Fe₂⁺ + 8H⁺ → Mn⁺₂ + 5Fe₃⁺+ 4H₂O

From the equation, we can see that one mole of permanganate (MnO₄⁻ ) reacts with 5 moles of iron (Fe₂⁺). Given that 1.0092 g of the iron salt is titrated with potassium permanganate, we can calculate the moles of iron and then use the volume of the permanganate solution to find its molarity.

First, calculate the moles of iron:

1.0092 g Fe(50.) H.₂O ÷ 392.2 g/mol = 0.002573 mol Fe

Next, use the stoichiometry of the balanced equation to find the moles of permanganate:

0.002573 mol Fe × (1 mol MnO⁻₄/ 5 mol Fe₂⁺) = 0.0005146 mol MnO⁻₄

Finally, divide the moles of permanganate by the volume of the solution in liters (converted from milliliters):

0.0005146 mol MnO⁻₄ / 0.02511 L = 0.0205 M