In a pottasium permanganate and oxalic acid titration..why do we add sulfuric acid to the oxalic acid solution and then boil it before titrating??
Doesn't the manganese in the MnO4 ion reduced to different levels in acid, alkaline,and neutral pH? In fact, if done in concentrated sulfuric acid, the result is different again, and should be done with caution.
The boiling is to complete the reaction. As I recall, boiling is not required, but a temp of greater than 80C is needed.
right. The elevated temperature helps the reduction take place; otherwise, it is slow, especially at the beginning of the titration. Later in the titration, after Mn^+2 are in solution, the reduction is much faster and the temperature is not critical which explains why there is no need to continue heating the solution.
In a potassium permanganate and oxalic acid titration, the addition of sulfuric acid to the oxalic acid solution and subsequent boiling serve important purposes.
1. Activation of Oxalic Acid: Addition of sulfuric acid helps to activate the oxalic acid by protonating it. This protonation promotes the formation of the oxalate ion and increases the reaction rate with potassium permanganate.
2. Removal of Dissolved Oxygen: Boiling the solution helps to remove any dissolved oxygen present in the solution. Oxygen can react with potassium permanganate, leading to inaccurate results and reducing the effectiveness of the titration.
3. Elimination of Interfering Substances: Boiling the solution with sulfuric acid also reduces the presence of any interfering substances that might react with or consume the potassium permanganate. This ensures that the potassium permanganate is available solely for the reaction with oxalic acid during the titration.
Overall, the addition of sulfuric acid and subsequent boiling of the solution in a potassium permanganate and oxalic acid titration helps to ensure accurate and reliable results by activating the oxalic acid, removing dissolved oxygen, and eliminating interfering substances.