Question

A potassium permanganate solution containing 1.58 g of KMnO4 per liter is added into 5 ml of an acidified iron (||) sulfate solution .Decolorizing of KMnO4 solution ceases when 10ml of the solution has been added.
Calculate the mass of FeSo4.7H2O which has been dissolved in one liter of solution.

Answers

mols KMnO4 = grams KMnO4/molar mass KMnO4.
M KMnO4 = mols/L

Here is the redox part of the reaction and I've balanced that part. You can finish it but the redox part is all that matters.
5Fe^2+ + MnO4^- --> 5Fe^3+ + Mn^2+

mols KMnO4 used = M x L = ?
Using the coefficients in the balanced equation, convert mols KMnO4 to mols Fe^2+.
Then g FeSO4.7H2O = mols FeSO4.7H2O x molar mass FeSO4.7H2O and that's the grams in 5 mL of the solution. Convert that to g in 1 L.
Thx

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