Calculation (4%)
1. A permanganate solution is prepared by dissolving 20.0123 g KMnO4 in 500 mL of distilled
water and boiled for 1 hour to remove any organic material. After filtration, the solution is
transferred to a 1.0 L volumetric flask and diluted to volume with distilled water. The
permanganate solution was titrated against 0.2046 M oxalic acid prepared in sulfuric acid
solution. A 50.00 mL aliquot of oxalic acid solution required 36.36 mL of permanganate
solution. A titration blank required 0.08 mL of permanganate. What is the permanganate
molarity? (The molecular mass of KMnO4 is 158.04 g/mol.)
5 H2C2O4 + 2 MnO4
-
+ 6 H
+
⇋
10 CO2 + 2 Mn
2+
+ 8 H2O