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.

Answer 1

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.

Answer 2

Thx