Copper(II) oxide dissolves in mineral acids such as hydrochloric acid, sulfuric acid or nitric acid to give the corresponding copper(II) salts:
: CuO + 2 HNO → Cu(NO) + HO
: CuO + 2 HCl → CuCl + HO
: CuO + HSO → CuSO + HO
In presense of water It reacts with concentrated alkali to form the corresponding cuprate salts:
: 2 MOH + CuO + HO → M[Cu(OH)]
: 2 NaOH + CuO + HO → Na[Cu(OH)]
It can also be reduced to copper metal using hydrogen, carbon monoxide, or carbon:
: CuO + H   →   Cu + HO
: CuO + CO   →   Cu + CO
: 2 CuO + C   →   2Cu + CO
When cupric oxide is substituted for iron oxide in thermite the resulting mixture is a low explosive, not an incendiary.