ABSTRACT
Chromium metal is largely used in the process of electroplating and in forming various alloys with ferrous and non-ferrous metals. In order to get pure chromium, the chromite ore is fused with NaOH to get sodium chromate and ferric oxide. The sodium chromate is soluble whereas, ferric oxide is insoluble. Sodium chromate is a yellow solid and a strong oxidising agent. Chromates, molybdates and tungstates exist both in solution and solid form. Molybdates and tungstates on acidification give a range of polymolybdates and polytungstates. It is important to note that chromates, manganates and ferrates are similar and occurring in the same row. Oxides of iron are the major source for iron extraction and it takes place in blast furnace. Small amount of iron is necessary in biological world of plant and animal whereas its large amount may become toxic much similar to Cu and Se.
