Preparation and Standardization of 0.02 M Potassium Permanganate

Potassium Permanganate Solution Preparation

• Dissolve 3.2 g of potassium permanganate in 1000 ml of water.
• Heat on a water-bath for 1 hour.
• Allow to stand for 2 days and filter through glass wool.
• Standardize the solution in the following manner.

Potassium Permanganate Solution Standardization

• To 25.0 ml of the solution in a glass-stoppered flask add 2 g of potassium iodide, followed by 10 ml of 1 M sulphuric acid. 
• Titrate the liberated iodine with 0.1 M sodium thiosulphate, using 3 ml of starch solution, added towards the end of the titration, as an indicator. 
• Perform a blank determination and make the necessary correction.
• Store protected from light.
• 1 ml of 0.1 M sodium thiosulphate is equivalent to 0.003161 g of KMnO4.

Also see: Determination of Shelf Life of Solutions in Laboratory