(7) Write the half reactions for the oxidation and reduction in the above reaction.
Copper oxidizes from a neutral atom to a oxidation state. The half reaction is therefore
Either the nitrogen or the oxygen must then be reduced. Since oxygen generally maintains an oxidation state of in compounds, it is reasonable to assume that the nitrogen is reduced. If the oxygen atoms in the nitrate ion do in fact have an oxidation state of , then the nitrogen must have an oxidation state of to create an ion with an overall charge of . Again, if the oxygen in the NO molecule has an oxidation state of , then the nitrogen must have an oxidation state of to create a neutral molecule. The second half reaction has the form
