Editing Copper(II) oxide (section)

==Reactions==
Copper(II) oxide reacts with [[mineral acid]]s such as [[hydrochloric acid]], [[sulfuric acid]], and [[nitric acid]] to give the corresponding hydrated copper(II) salts:<ref name=Brauer/>
: CuO + 2 HNO<sub>3</sub> → Cu(NO<sub>3</sub>)<sub>2</sub> + H<sub>2</sub>O
: CuO + 2 HCl → CuCl<sub>2</sub> + H<sub>2</sub>O
: CuO + H<sub>2</sub>SO<sub>4</sub> → CuSO<sub>4</sub> + H<sub>2</sub>O

In presence of water it reacts with concentrated [[alkali]] to form the corresponding [[cuprate]] salts:
: 2 NaOH + CuO + H<sub>2</sub>O → Na<sub>2</sub>[Cu(OH)<sub>4</sub>]

It can also be reduced to [[copper]] metal using [[hydrogen]], [[carbon monoxide]], and [[carbon]]:
: CuO + H<sub>2</sub>   →   Cu + H<sub>2</sub>O
: CuO + CO   →   Cu + CO<sub>2</sub>
: 2 CuO + C   →   2Cu + CO<sub>2</sub>
When cupric oxide is substituted for iron oxide in [[thermite]] the resulting mixture is a low explosive, not an incendiary.