... Usage: Mainly used in electric circuit electroplate area. Character:Cupric Oxide is the black non-finalize design powder or crystallize, pellet ... (monoclinic crystal) with density 6.313, melting rate 11.80KJ/mol, hardness 3.4, dielectric constant 18.10. It ... , it can be rescued by water, sand or extinguisher. Cupric Oxide Item Standard I Standard II CuO , % ≥9998Muriatic acid insoluble ...