The oxidation states of vanadium - Chemical elements: properties and reactions (4/8) - It's not difficult to bring a little of colour to the chemistry of vanadium. If I dissolve sodium vanadate in dilute acid, I get this solution. It's yellow because it contains the ion VO2+. I am going to shake this solution with zinc amalgam, which is made by stirring up zinc with mercury. The first new product has a rich blue colour. This is the ion VO2+. More shaking gives us a bottle-green tri-positive ion, V3+. There's one more stage and a lot of shaking to go. Eventually, the lavender colour of the aqueous dipositive ion, V2+, appears. Here's a shot of the starting material and our three products. Chemistry doesn't come much prettier than this.