Copper(II) acetate

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  Copper(II) acetate   
Names: copper(II) acetate
copper diacetate
cupric acetate
copper(II) ethanoate
verdigris

Formula: Cu(CH3COO)2
Cu(CH3COO)2 · H2O
SMILES: CC(=O)[O-].CC(=O)[O-].[Cu+2]
Molar mass: 181.634 g/mol (anhydrous)
199.649 g/mol (monohydrate)
Density: 1.93 g/cm3 (anhydrous)
1.882 g/cm3 (monohydrate)
Crystal system: triclinic (monohydrate)
Forms:
https://media.crystalls.info/w/uploads/media/Octahedron.json
https://media.crystalls.info/w/uploads/media/Truncated_octahedron.json
https://media.crystalls.info/w/uploads/media/Prolongated_octahedron.json


Color: dark-blue

dark-green black

Decomposition point: 115°C
388.15 K
239 °F
698.67 °R
(monohydrate)
240°C
513.15 K
464 °F
923.67 °R
(anhydrous)
Refractive index: 1.545 (monohydrate)
Electrical properties: dielectric
Magnetic properties: paramagnetic
Stability: slightly erodes (monohydrate)
Hardness: enough fragile, easy to crack
Toxicity: moderately toxic

Description

Organic compound, salt of bivalent transitional metal copper and organic acetic acid. From water solutions crystallizes as monohydrate.

Minerals

Occurs in nature as hoganite mineral.

Synthesis

Reaction between copper(II) hydroxycarbonate, hydroxide or oxide and acetic acid

Chemical equation:

4CH3COOH + Cu2CO3(OH)2 = 2Cu(CH3COO)2 + 3H2O + CO2
2CH3COOH + Cu(OH)2 = Cu(CH3COO)2 + H2O
2CH3COOH + CuO = Cu(CH3COO)2 + H2O

For preparation 100g of copper(II) acetate monohydrate a 55.38g of hydroxycarbonate, 48.87g of hydroxide or 39.84g of oxide and 85.94g of 70% acetic acid, 200.52g of 30% acetic acid or 668.42g of 9% acetic acid is required.
Add acid to the flask, then add small parts of copper compound with stirring until it will totally dissolve or, if you use carbonate, until carbon dioxide emission will stop. After reaction will stop, filter the solution and use it for crystal growing.

Reaction between metal copper, acetic acid and hydrogen peroxide

Chemical equation:

2CH3COOH + Cu + H2O2 = Cu(CH3COO)2 + 2H2O

For preparation 100g of copper(II) acetate monohydrate a 31.83g of copper, 567.90g of 3% peroxide or 56.79g of 30% peroxide and 85.94g of 70% acetic acid, 200.52g of 30% acetic acid or 668.42g of 9% acetic acid is required.
Add hot acid solution to the flask, then add peroxide and copper pieces, shavings or powder and stir and heat it until gas emission will stop.

Electrolysis of acetic acid solution with copper anode

Chemical equation:

2CH3COOH + Cu —electrolysis→ Cu(CH3COO)2 + H2

For preparation 100g of copper(II) acetate monohydrate a 31.83g of copper and 85.94g of 70% acetic acid, 200.52g of 30% acetic acid or 668.42g of 9% acetic acid is required.
Add to the flask acetic acid solution, then place there copper electrodes and plug them to 1.5-5 V power supply. After some time crystal growth will begin at cathode.


Reaction between copper(II) chloride, sulfate or nitrate and excess of concentrated acetic acid

Chemical equation:

2CH3COOH + CuCl2 = Cu(CH3COO)2↓ + 2HCl
2CH3COOH + CuSO4 = Cu(CH3COO)2↓ + H2SO4
2CH3COOH + Cu(NO3)2 = Cu(CH3COO)2↓ + 2HNO3

For preparation 100g of copper(II) acetate monohydrate a 85.39g of copper(II) chloride tetrahydrate, 67.34g of anhydrou scopper(II) chloride, 125.06g of copper(II) sulfate pentahydrate, 79.94g of anhydrous copper(II) sulfate, 148.08g of copper(II) nitrate hexahydrate or 93.94g of anhydrous copper(II) nitrate and 60.16g of glacial acid acetic or 85.94g of 70% acetic acid is required.
Add to the flask with hot copper compounds solution a acid solution with heating and stirring. Cooling this mixture will cause forming a large amount of crystalline precipitation. Filter precipitate and wash it wish small amount of glacial acetic acid, then filter the solution and use it for crystal growing.

Reaction between copper(II) nitrate and sodium acetate

Chemical equation:

2NaCH3COO + Cu(NO3)2 = Cu(CH3COO)2↓ + 2NaNO3

For preparation 100g of copper(II) acetate monohydrate a 148.08g of copper(II) nitrate hexahydrate or 93.94g of anhydrous copper(II) nitrate and 272.64g of sodium acetate trihydrate or 164.36g of anhydrous sodium acetate is required.
Add to the flask with hot copper(II) nitrate solution a sodium acetate solution with heating and stirring. Cooling this mixture will cause forming a large amount of crystalline precipitation. Filter precipitate and wash it wish small amount of cold water, then filter the solution and use it for crystal growing.

Reaction between copper(II) sulfate and calcium or lead(II) acetate

You can use copper(II) chloride instead of sulfate if you use lead salt.
Chemical equation:

Ca(CH3COO)2 + CuSO4 = Cu(CH3COO)2 + CaSO4
Pb(CH3COO)2 + CuSO4 = Cu(CH3COO)2 + PbSO4
Pb(CH3COO)2 + CuCl2 = Cu(CH3COO)2 + PbCl2

For preparation 100g of copper(II) acetate monohydrate a 85.39g of copper(II) chloride tetrahydrate, 67.34g of anhydrous copper(II) chloride, 125.06g of copper(II) sulfate pentahydrate or 79.94g of anhydrous copper(II) sulfate and 88.25g of calcium acetate monohydrate, 79.22g of anhydrous calcium acetate, 190.00g of lead(II) acetate trihydrate or 162.93g of anhydrous lead(II) acetate is required.
Add to the flask with calcium or lead acetate solution small parts of copper salt solution and stir. The large amount of poorly soluble precipitate will form. Settle it out and discard, then filter the solution carefully.

Influence of temperature

Growing at higher temperatures does not influence on growing speed but leads to compound hydrolysis.

Influence of impurities

Iron salts leads to obtaining polycrystalline, excrescences at main crystal and solution container walls and also to changing its color to dark-green.
Small addition of acetic acid is recommended for preventing hydrolysis and precipitation.

Addition of salts having different crystal lattice and non-reactive with compound - such as ammonium acetate, sodium acetate or sulfate - can increase the transparency of the solution and improve the shape of the crystals formed.

Storage conditions

Store in its original form or under several layers of varnish at average humidity and room temperature. Do not store in matchboxes or cotton wool and do not heat.

Solubility

Temperatureg/100g of waterg/100g of ethanolg/100g of methanolg/100g of acetoneg/100g of glycerolg/100g of pyridineg/100g of acetic acid
(anhydrous)(monohydrate)(monohydrate)(anhydrous)(anhydrous)(anhydrous)(anhydrous)(anhydrous)
15°C
288.15 K
59 °F
518.67 °R
0.48
0.48 g/100g
0.478 %
0.28
0.28 g/100g
0.279 %
10
10 g/100g
9.091 %
1.04
1.04 g/100g
1.029 %
20°C
293.15 K
68 °F
527.67 °R
~6.5
6.5 g/100g
6.103 %
7.2
7.2 g/100g
6.716 %
25°C
298.15 K
77 °F
536.67 °R
6.79
6.79 g/100g
6.358 %
7.14
7.14 g/100g
6.664 %
0.512
0.512 g/100g
0.509 %
30°C
303.15 K
86 °F
545.67 °R
~6.99
6.99 g/100g
6.533 %
0.925
0.925 g/100g
0.917 %
40°C
313.15 K
104 °F
563.67 °R
~7.38
7.38 g/100g
6.873 %
50°C
323.15 K
122 °F
581.67 °R
~7.78
7.78 g/100g
7.218 %
60°C
333.15 K
140 °F
599.67 °R
~8.17
8.17 g/100g
7.553 %
70°C
343.15 K
158 °F
617.67 °R
~8.57
8.57 g/100g
7.894 %
80°C
353.15 K
176 °F
635.67 °R
~8.96
8.96 g/100g
8.223 %
20.0
20 g/100g
16.667 %
90°C
363.15 K
194 °F
653.67 °R
~9.36
9.36 g/100g
8.559 %
100°C
373.15 K
212 °F
671.67 °R
9.75
9.75 g/100g
8.884 %
Soluble in diethyl ether. Slightly soluble in acetone. Insoluble in DMSO.

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