Copper oxide--------heat with H2----->Pink / reddish brown
solid J
what is J?
J = copper metal.
H2 'steals away' the oxygen from CuO to generate Cu, and itself
(ie. the H2) becomes H2O.
H2 has been oxidized from OS (oxidation state) of 0 (in H2) to
+1 (in H2O).
Cu has been reduced from OS of +2 (in CuO) to 0 (in Cu).
