Solving oxidation states

Range of vanadium oxidation states

Source: © Science Photo Library

Exceptions to Iupac’s definition means the rule still needs refinement

 Rules of thumb play a key role in chemical knowledge. Even though they often lack a rigorous definition, accepted concepts have proven useful for shedding light into chemical phenomena and, more importantly, achieving true predictions. There is, however, a concept of utmost relevance to chemistry which is flawed precisely because of its lack of a well-established definition: the oxidation state.