The Chemistry of Two Transition Elements

In this section, we look at the chemical properties of two transition elements, chromium and copper. Both elements are well known and commercially important in addition, they provide many examples of colorful compounds. 

A fascinating feature of chromium chemistry is the many colorful compounds of this element. In fact, this feature is the origin of the name chromium, which derives from the Greek word khroma, meaning color. The common oxidation states of chromium in compounds are +2, +3, and +6. 

The +6 oxidation state is represented by the chromate ion, Cr04 , and the dichromate ion, Cr207. Sodium chromate, Na2Cr04, which is yellow, and sodium 

Top Chromium metal reacts with hydrochloric acid to produce Cr(H20)6, which is blue.Boffom Cr(H20)6 oxidizes with air to give a chromium(lll) species, which is green. 

Vapors of ethanoi, C2H5OH, spontaneousiy ignite in the presence of the soiid oxide. 

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