Question
Imagine that you ran a similar titration as the lab experiment using a different iron sample with 0. 021 M KMnO4 as the titrant Calculate the percent of iron in the sample if the iron-containing sample weighed 0.67 grams. and the volume of the titnnt used was 35 . 74 mL (Use the net ionic equation. Equation (I), on page 1 ) When 0.2640 g of sodium oxalate (Na2C2O3) dissolved in a flask. it requires 30. 74 ml. of potassium permanganate (from a buret ) to titrate it to a light pink end point What is the molarity of the potassium permanganate The equation for this reaction is 5Na2C2O4(aq) + 2 KMnO2(aq) + 8H2sO4(aq) + K2SO4(aq) + 5Na2SO4(aq) + 10 CO3(g) + 8H2O
Explanation / Answer
6) MnO4-+5Fe2++8H+=5Fe3++Mn2++4H2O
[Fe2+]=5[MnO4-]=5*0.00075=0.00375 m=0.21g C%=(0.21/0.67)*100%=31.4%
7) moli(Na2C2O4)=0.00197 moli(KMnO4)=0.000788 [KMnO4]=0.00079moli*1000ml/30.74ml=0.0257mol/l