Calcium acetate

Calcium acetate

Calcium acetate crystals
Names
IUPAC name Calcium acetate
Other names Acetate of lime Calcium ethanoate Calcium diacetate
Identifiers
CAS Number	62-54-4 Y 5743-26-0 (monohydrate) N
3D model (Jmol)	Interactive image
Abbreviations	Ca(OAc)2
ChEBI	CHEBI:3310 Y
ChEMBL	ChEMBL1200800 N
ChemSpider	5890 Y
DrugBank	DB00258 Y
ECHA InfoCard	100.000.492
EC Number	269-613-0
E number	E263 (preservatives)
PubChem	6116
RTECS number	AF7525000
UNII	Y882YXF34X Y
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
SMILES [Ca+2].[O-]C(=O)C.[O-]C(=O)C
Properties
Chemical 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 (320 °F; 433 K)[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, hydrazine insoluble in acetone, ethanol and benzene
Acidity (pKa)	6.3-9.6
Refractive index (nD)	1.55
Pharmacology
ATC code	V03AE07 (WHO)
Hazards
NFPA 704	1 1 0
Autoignition temperature	680 to 730 °C (1,256 to 1,346 °F; 953 to 1,003 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	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).
N verify (what is YN ?)
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) or hydrated lime in vinegar:

CaCO_3(s) + 2CH₃COOH_(aq) → Ca(CH₃COO)_2(aq) + H₂O_(l) + CO_2(g)

Ca(OH)_2(s) + 2CH₃COOH_(aq) → Ca(CH₃COO)_2(aq) + 2H₂O_(l)

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.
• Calcium acetate is used as a food additive, as a stabilizer, buffer and sequestrant, mainly in candy products under the number E263. 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]

Ca(CH₃COO)₂ → CaCO_3(s) + (CH₃)₂CO_(v)

• 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; 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; 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