If 26.23 mL of potassium permanganate solution is required to titrate 1.041 g of ferrous ammonium sulfate hexahydrate, #FeSO_4(NH_4)_2SO_4 * 6H_2O#, chow do you calculate the molarity of the #KMnO_4# solution.?

Question

Noah Aldrich · Accepted Answer

You can do it like this:

Ferrous ammonium sulfate hexahydrate, 1.041 g, is what we have. The #sf(M_r=392.14)# #:.##sf(n_(Fe^(2+))=m/M_(r)=1.041/392.14=0.002654color(white)(x)"mol")# assemble the two 1/2 equations to create the equation: #sf(MnO_4^(-)+8H^++5erarrMn^(2+)+4H_2O" "color(red)((1)))# #sf(Fe^(2+)rarrFe^(3+)+e" "color(red)((2)))# To get the electrons to balance we need to X #sf(color(red)((2)))# by 5 then add to #sf(color(red)((1))rArr)# #sf(MnO_4^(-)+8H^++cancel(5e)+5Fe^(2+)rarrMn^(2+)+4H_2O+5Fe^(3+)+cancel(5e))# This tells that 5 moles of #sf(Fe^(2+))# react with 1 mole of #sf(MnO_4^-)# #:.##sf(n_(MnO_4^(-))=0.002654/5=5.3093xx10^(-4))# #sf(c=n/v)# The formula for [MnO_4^(-)] is 5.3093x10^(-4))/(26.23/1000) = 0.02024 color(white)(x)"mol/l").

Xavier Avery · Answer

undefined Use the formula:

$$ \text{Molarity (M)} = \frac{\text{Moles of KMnO}_4}{\text{Liters of solution}} $$

Calculate moles of KMnO₄ from the volume used and the balanced chemical equation. Then, convert the volume to liters and apply the formula.