Which of the following is (are) true for this reaction?
Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2(g)
I. It is an oxidation-reduction reaction.
II. Copper is oxidized.
III. The oxidation number of nitrogen goes from +5 to +4.
文字解釋
要怎麼看甚麼是reduced and oxidized