Standardization of 0.1 N potassium permanganate (KMnO4) is done by titrating 0.63 g of pure oxalic acid dissolved in water against KMnO4 until a pale pink color persists for 30 minutes, allowing calculation of the concentration of KMnO4. 1 g of ferrous sulfate is dissolved in water and acid, and titrated with standardized KMnO4 until a pale pink color appears, from which the amount of ferrous sulfate is calculated as 0.0278 g per 1 ml of 0.1 N KMnO4.

1. National college of pharmacy:
IP 1996,Vol.-2 page No 610.
Pharmaceutical Titrimetric analyses by A.A Napoleon page No 8.40
PROCEDURE.
Standardization of 0.1 N KMnO4
Weighed accurately about 0.63 g of pure oxalic acid and transferred into graduated
flask .dissolved in water and make up to 100ml. pipette out 20ml of the solution to a conical
flask. Add about 5ml of dilute H2SO4and warm the solution and then titrated against 0.1N
KMnO4 , end point is the appearance of pale pink colour persist for 30 min.
Assay of Ferrous sulphate
weighed accurately about 1g of ferrous sulphate dissolved about 25 ml of distilled water
to this add 20 ml of dilute H2SO4 and the solution is titrated with 0.1N KMnO4 , until a pale
pink colour obtained.
Each ml of 0.1N KMnO4 Equal to 0.0278 g of ferrous sulphate .