A solution of an iron compound in a reduced, unknown oxidation state (Fe n+ ) is

Question

A solution of an iron compound in a reduced, unknown oxidation state (Fen+) is given to you. The concentration of the solution is 3.000 M. How would you design a procedure to determine the oxidation state of the iron compound in the solution using potassium permanganate (KMnO4)?

In acidic solution, MnO4- will oxidize iron in any oxidation state to the +3 oxidation state. The number of electrons gained and lost must be equal: Moles of electrons lost by Fen+ = moles of electrons gained by MnO4-

In this case, however, Fen+ will be oxidized to Fe3+, so one mole of Fen+ will require (3-n) electrons in order to be oxidized to the +3 oxidation state. Thus we have: (3 - n) x (moles of Fen+ consumed) = 5 x (moles of MnO4- consumed)

You should be able to determine the necessary information and solve for n. Please show work.

Explanation / Answer

As in acidic medium, MnO4- changes to Mn2+

MnO4- + 8H+ + 5e- --> Mn2+ + 4H2O

and given, Fen+ --> Fe3+ + (3-n)e-

Now, to determine the oxidation state of iron in its compound one should have to know the amount of iron it takes for one mole of MnO4- let it say y then,

Fen+ --> Fe3+ + (3-n)e- ] x y  

no. of electron = (3-n)y

Moles of electrons lost by Fen+ = moles of electrons gained by MnO4-

(3-n)y = 5

here y is the concentration of fe compound and n is the unknown oxidation state.

So, by this way, you can easily calculate the oxidation state of iron.

if you satisfied please like it.. thanks....

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