Oxidation States of Vanadium

Oxidation States of Vanadium
Vanadium is an interesting transition element we find in the middle of the Periodic Table. Vanadium can go through multiple oxidation states. Its ions can have different charges, and we’d like to show you that. Here we’ve poured off some water from a zinc mercury amalgam and placed it in this large Erlenmeyer flask. Here we have the ammonium metavanadate solution which we notice is yellow in color when vanadium is in the plus-5 oxidation state. As we add the plus-5 vanadium to the catalyst, stoppering the flask, agitating it slightly, we see it changing to a green color. If we continue to agitate it and allow the reaction to proceed further, we notice a blue color appearing. This would be the vanadium in the 3-positive oxidation state. And finally, with a great deal of agitation, allowing the vanadium and the plus-3 to come in contact with the catalyst, zinc mercury amalgam…after vigorous shaking, we see that the vanadium has changed from the 3-positive, in the blue, to the 2-positive, which is the violet color.