AIM:- To perform limits test for iron. Apparatus:- Nessler's cylinder, Glass rod, Measuring cylinder, pipette, dropper, Chemicals required:- citric acid 20% w/v, ammonia 10%w/v,ferric ammonium sulphate,thioglycolic acid. - Iron free citric acid 20 % w/v solution of Citric acid. 20g of citric acid in 100 ml of water Ammonia 10% w/v of ammonia in water. Preparationo standard iron solution:- • Weigh accurately 0. 1728 g of ferric ammonium sulphate and dissolve it in 10 ml of 0.1N sulfuric acid and make up to 1000 ml with water. • 1ml = 0. 02 mg of Fe. THEORY/Principal:- The limit test for iron is based on the reaction of iron in ammonical solution in the presence of citric acid with thioglycolic acid. When a pale pink to deep reddish purple color is formed due to the ferrous thioglycote complex. The color produced from a specific amount of subst...
