titrat m/20 oxzlic acid(20 ml) of by KMnO4
To determine the concentration of oxalic acid using a titration method with potassium permanganate (KMnO4), follow these steps:
1. Prepare the KMnO4 solution: Dissolve a known mass of potassium permanganate (KMnO4) in distilled water to create a standard KMnO4 solution. The specific concentration of this solution will depend on the purpose of the titration.
2. Measure the volume of oxalic acid solution: Using a volumetric flask or pipette, measure 20 ml of the oxalic acid solution and transfer it to a clean titration flask.
3. Set up the titration apparatus: Place the titration flask containing the oxalic acid solution on a white tile or a suitable surface. Position the burette filled with the standard KMnO4 solution above the flask. Add a few drops of a suitable indicator, such as phenolphthalein or potassium iodide, to the oxalic acid solution.
4. Start the titration: Gradually add the KMnO4 solution from the burette into the oxalic acid solution. The KMnO4 solution will react with the oxalic acid, causing a color change or other observable indicator change.
5. Observe the endpoint: Continue adding the KMnO4 solution until a permanent color change occurs, indicating the endpoint of the reaction. Note the volume of KMnO4 solution required to reach the endpoint.
6. Perform calculations: Use stoichiometry to determine the molarity (concentration) of the oxalic acid solution. The balanced chemical equation between oxalic acid (C2H2O4) and KMnO4 is as follows:
5C2H2O4 + 2KMnO4 + 3H2SO4 -> 2MnSO4 + 10CO2 + 8H2O + K2SO4
From the balanced equation, you can determine the ratio between the oxalic acid and KMnO4. By using the volume of KMnO4 solution required to reach the endpoint, you can calculate the moles of KMnO4 used. Then, based on the stoichiometry, you can determine the moles of oxalic acid present in the 20 ml solution.
Finally, you can calculate the concentration of the oxalic acid solution by dividing the moles of oxalic acid by the volume of the solution in liters.
Note: The molar ratio between oxalic acid and KMnO4 (from the balanced equation) and the molarity of the KMnO4 solution are essential to accurately determine the concentration of the oxalic acid solution.