We did an experiment where we dissolved .239g of an iron complex into a solution of 30 mL of water, 10 mL of 3M sulfuric acid, and 5 mL of phosphoric acid. We tritrated the solution with potassium permanganate (it took 46.5 mL to turn the solution pink).
I need to find the molarity of the potassium permanganate solution. I don't exactly know how to go about this, especially since I don't know the molarity of the phosphoric acid. Can anyone help?
I need to find the molarity of the potassium permanganate solution. I don't exactly know how to go about this, especially since I don't know the molarity of the phosphoric acid. Can anyone help?
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Potassium permanganate is an oxidizing agent so this is probably a redox titration rather than an acid-base titration. The amount of acid is probably irrelevant for the titration itself - though it might be important for sample preparation depending on what complex of iron is used.
My best guess is that in the redox reaction Fe2+ will be oxidized to Fe3+ and MnO4- will be reduced to MnO2(s). The starting point would be to write a balanced redox reaction between Fe2+ and MnO4- in acid conditions and then use the number of mol of Fe2+ to find the # mol of permanganate and its concentration.
However you do not give enough information to do the calculation or to be sure of the reaction. What is the complex? You need some way to find #mol Fe2+ that you start with.
My best guess is that in the redox reaction Fe2+ will be oxidized to Fe3+ and MnO4- will be reduced to MnO2(s). The starting point would be to write a balanced redox reaction between Fe2+ and MnO4- in acid conditions and then use the number of mol of Fe2+ to find the # mol of permanganate and its concentration.
However you do not give enough information to do the calculation or to be sure of the reaction. What is the complex? You need some way to find #mol Fe2+ that you start with.