Editing Copper(II) oxide (section)

==Production==
It is produced on a large scale by [[pyrometallurgy]], as one stage in extracting copper from its ores. The ores are treated with an aqueous mixture of [[ammonium carbonate]], [[ammonia]], and [[oxygen]] to ultimately give copper(II) [[ammine complex]] carbonates, such as {{chem2|[Cu(NH3)4]CO3}}. After extraction from the residues and after separation from iron, lead, etc. impurities, the carbonate salt is decomposed with steam to give CuO.<ref name=Ullmann/>  

It can be formed by heating copper in air at around 300–800&nbsp;°C:
: {{chem2|2 Cu + O2 → 2 CuO}}
For laboratory uses, copper(II) oxide is conveniently prepared by pyrolysis of [[copper(II) nitrate]] or [[basic copper(II) carbonate]]:<ref name=Brauer>{{cite book|author=O. Glemser and H. Sauer |chapter=Copper, Silver, Gold|title=Handbook of Preparative Inorganic Chemistry, 2nd Ed. |editor=G. Brauer|publisher=Academic Press|year=1963|place=NY, NY|volume=1}}</ref>  
: {{chem2|2 Cu(NO3)2 → 2 CuO  + 4 NO2  + O2}}  (180°C)
: {{chem2|Cu2(OH)2CO3 → 2 CuO + CO2 + H2O}}
Dehydration of cupric hydroxide has also been demonstrated:
:{{chem2|Cu(OH)2 → CuO + H2O}}