|Name||Copper (II) - acetate|
|Other names||Verdigris, cupric acetate, Kupferdiacetat|
|CAS number||142-71-2 (water-free), 6046-93-1 (mono hydrate)|
|Short description||becomes green (water-free) to bluish green (mono hydrate), odorless crystals|
|Mol mass||181,64 g/mol|
|State of aggregation||firmly|
|Density||1,883 kg/m (mono hydrate)|
|Melting point||115 "°C (mono hydrate)|
|Boiling point||- "°C; Decomposition with 240 "°C|
|Steam pressure||- Pa (x "°C)|
|Solubility||solubly in water a little solubly in alcohol|
|R and S-sentences||R: 22S: 36|
|As far as possible and common, SI-UNITs are used. If not differently notes, the indicated data apply with standard conditions.|
Copper (II) - acetate (also verdigris; lat. Cuprum aceticum) is the cuprous salt of acetic acid.
Copper (II) - acetate crystallized from aqueous solutions with a mol of crystal water, the composition is thus cu (CH3COO) 2 x H2O. This connection forms dark-green crystals, which separate in water (with 20 "°C to 72g/l) and ethanol. The crystals weather gradually at air and lose with heating up on over 100 "°C its crystal water, starting from 240 "°C decompose them, whereby about 70% of contained carbon evaporate as acetic acid.
Copper acetate forms in the laboratory when adjusting copper sheet or - for wire in acetic acid or vinegar at air. First verdigris so mentioned, a mixture the different basic copper acetates forms presents itself and in copper places, which are above the acetic acid solution form. Verdigris forms therefore also when keeping essighaltigen meals in copper containers. Verdigris (approximate composition cu (CH3COO) 2 [cu (OH) 2] 3 2H2O) may not be confounded however with the green layers of a patina, this is copper (carbonate sulfate chloride) - hydroxide mixtures (basic copper connections), which form e.g. on copper roofs.
In acetic acid solved verdigris supplies then copper acetate with the technical production of copper acetate with acetic acid becomes instead of copper metal copper (II) - oxide or copper (II) - carbonate uses.
Copper acetate is a Farbpigment (Spanish green) in the colors green (also verdigris) to blue (in mixture with lime and acetic acid, it forms, this for copper calcium acetate frequently in the Middle Ages used), it is important intermediate product for the production of the poisonous Farbpigments Schweinfurter green and it serves as fungicide (mushroom-killing means) and is moderately poisonous. In the Bengali light and fireworks it supplies a green flame coloration.