A known amount of hydroxylamine hydrochloride is reacted with ferric ion which is reduced to ferrous ion.
Potassium permanganate is used to re-oxidize the ferrous ion back to ferric ion.
If the concentration and amount of the permanganate solution are known then the amount of ferrous ion titrated can be calculated. This amount is equal to the amount of ferric ion that originally reacted with the hydroxylamine hydrochloride. The number of electrons transferred as each ferric ion is reduced to ferrous is one, therefore, the total number of electrons lost per hydroxylamine hydroxide can be calculated and the new oxidation state of nitrogen determined. All of the solutions in this experiment are skin and eye irritants. The potassium permanganate solution will oxidize skin and clothing.