Ammonium acetate

Ammonium acetate, also known as spirit of Mindererus in aqueous solution, is a chemical compound with the formula NH4CH3CO2. It is a white, hygroscopic solid and can be derived from the reaction of ammonia and acetic acid. It is available commercially.[5]

Ammonium acetate
Names
IUPAC name
Ammonium ethanoate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.010.149
E number E264 (preservatives)
RTECS number
  • AF3675000
UNII
Properties
C2H7NO2
Molar mass 77.083 g·mol−1
Appearance White solid crystals, deliquescent
Odor Slightly acetic
Density 1.17 g/cm3 (20 °C)[1]
1.073 g/cm3 (25 °C)
Melting point 113 °C (235 °F; 386 K) [2]
102 g/100 mL (0 °C)
148 g/100 mL (4 °C)[1]
143 g/100 mL (20 °C)
533 g/100 mL (80 °C)
Solubility Soluble in alcohol, SO2, acetone, liquid ammonia[3]
Solubility in methanol 7.89 g/100 mL (15 °C)[4][1]
131.24 g/100 g (94.2 °C)[3]
Solubility in dimethylformamide 0.1 g/100 g[3]
Acidity (pKa) 9.9
Basicity (pKb) 33
-41.1·10−6 cm3/mol
Viscosity 21
Structure
Orthorhombic
Thermochemistry
−615 kJ/mol[3]
Hazards
Main hazards Irritant
Safety data sheet JT Baker
GHS pictograms [4]
GHS Signal word Warning
H303, H316, H320, H333[4]
P281, P335[4]
NFPA 704 (fire diamond)
Flash point 136 °C (277 °F; 409 K) [4]
Lethal dose or concentration (LD, LC):
386 mg/kg (mice, intravenous)[3]
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

Uses

It is the main precursor to acetamide:[6]

NH4CH3CO2 → CH3C(O)NH2 + H2O

It is also used as a diuretic.[5]

Buffer

As the salt of a weak acid and a weak base, ammonium acetate is often used with acetic acid to create a buffer solution. Ammonium acetate is volatile at low pressures. Because of this, it has been used to replace cell buffers with non-volatile salts in preparing samples for mass spectrometry.[7] It is also popular as a buffer for mobile phases for HPLC with ELSD detection for this reason. Other volatile salts that have been used for this include ammonium formate.

Other
  • a biodegradable de-icing agent.
  • a catalyst in the Knoevenagel condensation and as a source of ammonia in the Borch reaction in organic synthesis.
  • a protein precipitating reagent in dialysis to remove contaminants via diffusion.
  • a reagent in agricultural chemistry for determination of soil CEC (cation exchange capacity ) and determination of available potassium in soil wherein the ammonium ion acts as a replacement cation for potassium.

Food additive

Ammonium acetate is also used as a food additive as an acidity regulator; INS number 264. It is approved for usage in Australia and New Zealand.[8]

Production

Ammonium acetate is produced by the neutralization of acetic acid with ammonium carbonate or by saturating glacial acetic acid with ammonia.[9] Obtaining crystalline ammonium acetate is difficult on account of its hygroscopic nature.

References
  1. Pradyot, Patnaik (2003). Handbook of Inorganic Chemicals. The McGraw-Hill Companies, Inc. ISBN 0-07-049439-8.
  2. Davidson, Arthur W.; McAllister, Walter H. (1930). "SOLUTIONS OF SALTS IN PURE ACETIC ACID. II. SOLUBILITIES OF ACETATES1". Journal of the American Chemical Society. 52 (2): 507–519. doi:10.1021/ja01365a010. ISSN 0002-7863.
  3. http://chemister.ru/Database/properties-en.php?dbid=1&id=354
  4. "Safety Data Sheet of Ammonium Acetate" (PDF). tedia.com. Tedia Company Inc. 2011-08-12. Retrieved 2014-06-10.
  5. Hosea Cheung; Robin S. Tanke; G. Paul Torrence. "Acetic Acid". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a01_045.pub2.
  6. Coleman, G. H.; Alvarado, A. M. (1923). "Acetamide". Organic Syntheses. 3: 3.; Collective Volume, 1, p. 3
  7. Berman, Elena S. F.; Fortson, Susan L.; Checchi, Kyle D.; Wu, Ligang; Felton, James S.; Kuang Jen, J. Wu; Kulp, Kristen S. (2008). "Preparation of single cells for imaging/profiling mass spectrometry". J Am Soc Mass Spectrom. 19: 1230–1236. doi:10.1016/j.jasms.2008.05.006.
  8. Australia New Zealand Food Standards Code "Standard 1.2.4 - Labelling of ingredients". Retrieved 2011-10-27.
  9. Brannt, William (1914). A practical treatise on the manufacture of vinegar. Lancaster, PA: Henry Carey Baird & Co. pp. 316–317.
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