Calcium acetate

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Edgar181 (talk | contribs) at 12:32, 1 March 2010 (water). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Calcium acetate
Names
IUPAC name
Calcium acetate
Other names
Acetate of lime
Calcium ethanoate
Identifiers
3D model (JSmol)
Abbreviations Ca(OAc)2
ChemSpider
ECHA InfoCard 100.000.492 Edit this at Wikidata
E number E263 (preservatives)
  • InChI=1/2C2H4O2.Ca/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2
    Key: VSGNNIFQASZAOI-NUQVWONBAW
  • [Ca+2].[O-]C(=O)C.[O-]C(=O)C
Properties
C4H6CaO4
Molar mass 158.166 g·mol−1
Appearance White solid
hygroscopic
Density 1.6 g/cm3
Melting point 160 °C
37.4 g/100 mL (0 °C)
34.7 g/100 mL (20 °C)
29.7 g/100 mL (100 °C)
Solubility slightly soluble in methanol
insoluble in acetone, ethanol and benzene
Acidity (pKa) 6.3-9.6
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Lethal dose or concentration (LD, LC):
4280 mg/kg (oral, rat)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

The chemical compound calcium acetate is the calcium salt of acetic acid. It has the formula Ca(C2H3O2)2. Its standard name is calcium acetate, while calcium ethanoate is the systematic IUPAC name. An older name is acetate of lime. The anhydrous form is very hygroscopic; therefore the monohydrate (Ca(CH3COO)2.H2O, CAS [5743-26-0]) is the common form.

If an alcohol is added to a saturated solution of calcium acetate, a semisolid, flammable gel forms that is much like "canned heat" products such as Sterno.[1] Chemistry teachers often prepare "California Snowballs", a mixture of calcium acetate solution and ethanol. The resulting gel is whitish in color, and can be formed to resemble a snowball.

Calclacite is a name for calcium acetate chloride pentahydrate, which is treated as mineral species but possess anthropogenic origin.

History

Because it is inexpensive, calcium acetate was once a common starting material for the synthesis of acetone before the development of the cumene process.[2] [3]

Calcium Acetate can be prepared by soaking eggshells in vinegar. Since both reagents would have been available pre-historically, the chemical would have been observable as crystals then.

Uses

In kidney disease, blood levels of phosphate may rise (called hyperphosphatemia) leading to bone problems. Calcium acetate binds phosphate in the diet to lower blood phosphate levels. Side effects of this treatment include upset stomach.

Calcium acetate is used as a food additive, as a stabilizer, buffer and sequestrant, mainly in candy products. It also neutralizes fluoride in water.

References

  1. ^ "Canned Heat" at Journal of Chemical Education "Chemistry comes alive!"
  2. ^ Leo Frank Goodwin and Edward Tyghe Sterne (1920). "Losses Incurred in the Preparation of Acetone by the Distillation of Acetate of Lime". Industrial & Engineering Chemistry. 12 (3): 240–243. doi:10.1021/ie50123a012.
  3. ^ E. G. R. Ardagh, A. D. Bbarbour, G. E. McClellan, and E. W. McBride (1924). "Distillation of Acetate of Lime". Industrial & Engineering Chemistry. 16 (11): 1133–1139. doi:10.1021/ie50179a013.{{cite journal}}: CS1 maint: multiple names: authors list (link)