For the reaction - (This reaction applies to questions 1, 2, 3, and question 4 to a degree….)
16 H++ 2 MnO41-+ 5 C2O42-→2 Mn2+ +8 H2O +10 CO2
1. What is the normality of an unknown H2C2O4 solution if 10.0 mL of the solution required 32.0 mL of 0.105 M KMnO4 to react with it completely?
2. A potassium permanganate solution was standardized against H2C2O4 and found to be 0.230 N KMnO4. Calculate the mass of KMnO4 contained in 250 mL of solution. Also, calculate the molarity of the solution.
3. Explain using mathematical equations and words how to make1000.0 mL of a 0.100 N KMnO4 solution using an unlimited amount of 0.485 NKMnO4 solution, distilled water, and a 1000 mL volumetric flask.
4. A 0.250 N H2C2O4 solution was prepared by dissolving solid oxalic acid dihydrate (H2C2O4 .2 H2O) in distilled water. What mass of the solid was used to prepare 750 mL of this solution. Show this work from an acid/base and redox point of view.
5. Tetraarsenic hexoxide, As4O6, is frequently used as a primary standard for KMnO4 solutions. However, As4O6 is insoluble in water, so it is usually dissolved in NaOH solution:
4 Na OH + As4O6 → 4 NaAsO2 + 2 H2O
The resulting solution is acidified with hydrochloric acid:
NaAsO2 + HCl → HAsO2 + NaCl
Finally, the solution is titrated with KMnO4 solution. The above reactions do not involve oxidation-reduction; they only prepare the solution for titration with KMnO4 solution.
a) Balance the following equation:
KMnO4 + HAsO2 + H2O + HCl → KCl + MnCl2 + H3AsO4
b) A 0.05284 g sample of tetraarsenic hexoxide was dissolved in sodium hydroxide solution and acidified with hydrochloric acid solution. It required 30.0 mL of potassium permanganate solution for complete oxidation. Calculate:
(i) Normality of the potassium permanganate solution
(ii) Molarity of the potassium permanganate solution
(iii) # of grams of KMnO4 in the 30.0 mL of solution.
(iii) # of moles of potassium chloride produced.