Engineering Chemistry

6

ESTIMATION OF FERROUS IRON BY DICHROMETRY

AIM

To estimate the amount of ferrous iron present in 100 ml of the given solution by using approximately 0.05N potassium dichromate solution.

PRINCIPLE

The estimation is based on redox titration. Ferrous iron is estimated by dichrometry using diphenylamine indicator. Potassium dichromate oxidises ferrous iron to ferric iron in an acidic medium.

The addition of orthophosphoric acid is to reduce the redox potential of the ferrous to ferric iron and to obtain the sharp change of the end point of titration from a colourless to a permanent violet blue colour solution.

PROCEDURE

Part A: Preparation of Standard ...