Calcium acetate

Calcium acetate
Calcium acetate crystals
IUPAC name Calcium acetate
Other names Acetate of lime Calcium ethanoate Calcium diacetate
Identifiers
Abbreviations	Ca(OAc)2
CAS number	62-54-4 Y, 5743-26-0 (monohydrate) Y
PubChem	6116
ChemSpider	5890 Y
UNII	Y882YXF34X Y
DrugBank	DB00258
ChEBI	CHEBI:3310 Y
ChEMBL	CHEMBL1200800 N
RTECS number	AF7525000
ATC code	A12AA12,(anhydrous)
Jmol-3D images	{{#if:[Ca+2].[O-]C(=O)C.[O-]C(=O)C|Image 1
SMILES [Ca+2].[O-]C(=O)C.[O-]C(=O)C
InChI InChI=1S/2C2H4O2.Ca/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Y Key: VSGNNIFQASZAOI-UHFFFAOYSA-L Y InChI=1/2C2H4O2.Ca/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Key: VSGNNIFQASZAOI-NUQVWONBAW
Properties
Molecular formula	C4H6CaO4
Molar mass	158.17 g mol−1
Appearance	White solid hygroscopic
Odor	slight acetic acid odor
Density	1.509 g/cm3
Melting point	160 °C[1] (decomposition to CaCO3 + acetone)
Solubility in water	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
Refractive index (nD)	1.55
Hazards
NFPA 704	1 1 0
Autoignition temperature	680-730 °C
LD50	4280 mg/kg (oral, rat)
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Calcium acetate is a chemical compound which is a calcium salt of acetic acid. It has the formula Ca(C₂H₃O₂)₂. Its standard name is calcium acetate, while calcium ethanoate is the systematic name. An older name is acetate of lime. The anhydrous form is very hygroscopic; therefore the monohydrate (Ca(CH₃COO)₂•H₂O) is the common form.

Production

Calcium acetate can be prepared by soaking calcium carbonate (found in eggshells, or in common carbonate rocks such as limestone or marble) in vinegar:

CaCO₃ + 2CH₃COOH → Ca(CH₃COO)₂ + H₂O + CO₂

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.^[2]
• Because it is inexpensive, calcium acetate was once a common starting material for the synthesis of acetone before the development of the cumene process.^[3][4]
• A saturated solution of calcium acetate in alcohol forms a semisolid, flammable gel forms that is much like "canned heat" products such as Sterno.^[5]
  • Chemistry teachers often prepare "California Snowballs", a mixture of calcium acetate solution and ethanol.^[6] The resulting gel is whitish in color, and can be formed to resemble a snowball.

References

1. ↑ Dale L. Perry (May 19, 2011). Handbook of Inorganic Compounds (Second ed.). Taylor & Francis. p. 84. ISBN 978-1-4398-1461-1. 
2. ↑ Polymeric calcium phosphate cements: setting reaction modifiers
3. ↑ 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. 
4. ↑ E. G. R. Ardagh, A. D. Barbour, G. E. McClellan, and E. W. McBride (1924). "Distillation of Acetate of Lime.". Industrial & Engineering Chemistry 16 (11): 1133–1139. doi:10.1021/ie50179a013. 
5. ↑ "Canned Heat" at Journal of Chemical Education "Chemistry comes alive!"
6. ↑ Chemistry Teaching Resources