Write the half-reaction for the oxidation occurring in the following redox reaction: Cr(s) + Zn2+ (aq) → Cr+(aq) + Zn(s)

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .