Difference between revisions of "Copper citrate"

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| ImageCaption = Anhydrous (left) and hydrated (right) copper citrate.
 
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| Appearance = Blue solid (anhydrous)<br>Green solid (hemipentahydrate)
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| Appearance = Blue solid (anhydrous)<br>Turquoise (hemipentahydrate)
 
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| Odor = Odorless
 
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| SolubleOther = Insoluble in halocarbons, hydrocarbons
 
| SolubleOther = Insoluble in halocarbons, hydrocarbons
 
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| VaporPressure = ~0 mmHg
 
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==Properties==
 
==Properties==
 
===Chemical===
 
===Chemical===
 
 
Copper citrate is soluble in alkaline citrate solutions.
 
Copper citrate is soluble in alkaline citrate solutions.
  
 
The hydrated salt will lose its water of crystallization at 100 °C, turning from green to blue.  
 
The hydrated salt will lose its water of crystallization at 100 °C, turning from green to blue.  
  
When heated more strongly, the salt decomposes, leaving behind solid copper particles. When heated under vacuum, the residue is claimed to be pyrophoric <ref>Gorrie, T., Kopf, P., & Toby, S. (1967). Kinetics of the reaction of some pyrophoric metals with oxygen. The Journal of Physical Chemistry, 1478(4), 3842–3845. Retrieved from http://pubs.acs.org/doi/pdf/10.1021/j100871a019</ref>
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When heated more strongly, the salt decomposes, leaving behind solid copper particles. When heated under vacuum, the residue is claimed to be pyrophoric.<ref>Gorrie, T., Kopf, P., & Toby, S. (1967) Kinetics of the reaction of some pyrophoric metals with oxygen. The Journal of Physical Chemistry, 1478(4), 3842–3845. Retrieved from http://pubs.acs.org/doi/pdf/10.1021/j100871a019</ref>
  
 
===Physical===
 
===Physical===
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Copper citrate is a blueish solid, soluble in water.
  
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==Preparation==
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Copper citrate can be made by reacting [[copper(II) oxide]] or hydroxide with [[citric acid]].
  
==Preparation==
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: 3 CuO + 2 C<sub>6</sub>H<sub>8</sub>O<sub>7</sub> → Cu<sub>3</sub>C<sub>12</sub>H<sub>10</sub>O<sub>14</sub> + 3 H<sub>2</sub>O
Copper citrate can be made by reacting copper oxide or hydroxide with citric acid.
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Copper citrate has a low solubility in water, and can be prepared by precipitation from aqueous solution containing copper and citrate ions. A procedure is available from the Royal Society for Chemistry<ref>
 
Copper citrate has a low solubility in water, and can be prepared by precipitation from aqueous solution containing copper and citrate ions. A procedure is available from the Royal Society for Chemistry<ref>
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==Projects==
 
==Projects==
 
*Make pyrophoric copper
 
*Make pyrophoric copper
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*Compound collecting
  
 
==Handling==
 
==Handling==
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===Storage===
 
===Storage===
In closed bottles, or sealed if you want the anhydrous form.
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Copper citrate should be kept in closed bottles, or air tight sealed ones if you want the anhydrous form.
  
 
===Disposal===
 
===Disposal===

Revision as of 15:46, 5 June 2019

Copper citrate
Copper citrate dehydration.jpg
Anhydrous (left) and hydrated (right) copper citrate.
Names
IUPAC name
Copper 2-hydroxypropane-1,2,3-tricarboxylate
Other names
Cuprocitrol
Properties
Cu3C12H10O14
Molar mass 568.85 g/mol
Appearance Blue solid (anhydrous)
Turquoise (hemipentahydrate)
Odor Odorless
Boiling point Decomposes
Slightly soluble
Solubility Insoluble in halocarbons, hydrocarbons
Vapor pressure ~0 mmHg
Hazards
Safety data sheet None
Related compounds
Related compounds
Copper(II) acetate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Copper(II) citrate, also known as cuprocitrol, is an ionic compound of copper and citric acid with the formula Cu3(C6H5O7)2 or Cu3C12H10O14, with a molecular weight of 568.85 g/mol. Some resources incorrectly list its formula as Cu2C6H4O7 and a molecular weight of 360.2 g/mol, but this formulation would require the citric acid molecule to lose more protons than it has carboxylic groups. It exists as a seafoam green hemipentahydrate and a sky-blue anhydrous solid.

Properties

Chemical

Copper citrate is soluble in alkaline citrate solutions.

The hydrated salt will lose its water of crystallization at 100 °C, turning from green to blue.

When heated more strongly, the salt decomposes, leaving behind solid copper particles. When heated under vacuum, the residue is claimed to be pyrophoric.[1]

Physical

Copper citrate is a blueish solid, soluble in water.

Preparation

Copper citrate can be made by reacting copper(II) oxide or hydroxide with citric acid.

3 CuO + 2 C6H8O7 → Cu3C12H10O14 + 3 H2O

Copper citrate has a low solubility in water, and can be prepared by precipitation from aqueous solution containing copper and citrate ions. A procedure is available from the Royal Society for Chemistry[2] describing its preparation from citric acid or trisodium citrate and copper acetate or sulfate. However, when followed, the reaction proceeds only very slowly, and deposits the product as a crust. Heating the mixture will accelerate the reaction and give a finely-divided product.

Magnesium citrate, available in solution as a laxative, can also be used in place of trisodium citrate.

Projects

  • Make pyrophoric copper
  • Compound collecting

Handling

Safety

Copper citrate is fairly benign.

Storage

Copper citrate should be kept in closed bottles, or air tight sealed ones if you want the anhydrous form.

Disposal

Copper citrate should be disposed of just any other copper compound.

Gallery

References

  1. Gorrie, T., Kopf, P., & Toby, S. (1967) Kinetics of the reaction of some pyrophoric metals with oxygen. The Journal of Physical Chemistry, 1478(4), 3842–3845. Retrieved from http://pubs.acs.org/doi/pdf/10.1021/j100871a019
  2. Preparation of copper(II) citrate. RSC Student worksheet, http://www.rsc.org/learn-chemistry/resource/download/res00000903/cmp00001141/pdf

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