Ammonium acetate

Ammonium acetate
Ammonium acetate skeletal formula
Ball-and-stick model of ammonium acetate
Crystalline of ammonium acetate
Names
IUPAC name
Ammonium ethanoate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.010.149 Edit this at Wikidata
EC Number
  • 211-162-9
RTECS number
  • AF3675000
UNII
UN number 3077
  • InChI=1S/C2H4O2.H3N/c1-2(3)4;/h1H3,(H,3,4);1H3 checkY
    Key: USFZMSVCRYTOJT-UHFFFAOYSA-N checkY
  • InChI=1/C2H4O2.H3N/c1-2(3)4;/h1H3,(H,3,4);1H3
    Key: USFZMSVCRYTOJT-UHFFFAOYAY
  • O=C([O-])C.[N+H4]
Properties
C2H7NO2
Molar mass 77.083 g·mol−1
Appearance White solid crystals, deliquescent
Odor Slightly acetic acid like
Density 1.17 g/cm3 (20 °C)[1]
1.073 g/cm3 (25 °C)
Melting point 113 °C (235 °F; 386 K)[4]
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[2]
Solubility in methanol 7.89 g/100 mL (15 °C)[3][1]
131.24 g/100 g (94.2 °C)[2]
Solubility in dimethylformamide 0.1 g/100 g[2]
Acidity (pKa) 9.9
Basicity (pKb) 33
-41.1·10−6 cm3/mol
Viscosity 21
Structure
Orthorhombic
Thermochemistry
−615 kJ/mol[2]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Irritant
GHS labelling:[3]
GHS07: Exclamation mark
Warning
H303, H316, H320, H333
P281, P335
NFPA 704 (fire diamond)
[3]
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 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
1
1
1
Flash point 136 °C (277 °F; 409 K)[3]
Lethal dose or concentration (LD, LC):
386 mg/kg (mice, intravenous)[2]
Safety data sheet (SDS) JT Baker
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

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]

History

The synonym Spirit of Mindererus is named after R. Minderer, a physician from Augsburg.[6]

Uses

It is the main precursor to acetamide:[7]

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 that contain non-volatile salts in preparing samples for mass spectrometry.[8] It is also popular as a buffer for mobile phases for HPLC with ELSD and CAD-based detection for this reason. Other volatile salts that have been used for this include ammonium formate.

When dissolving ammonium acetate in pure water, the resulting solution typically has a pH of 7, because the equal amounts of acetate and ammonium neutralize each other. However, ammonium acetate is a dual component buffer system, which buffers around pH 4.75 ± 1 (acetate) and pH 9.25 ± 1 (ammonium), but it has no significant buffer capacity at pH 7, contrary to common misconception.[9]

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.
  • part of Calley's method for lead artifact conservation

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.[10]

Production

Ammonium acetate is produced by the neutralization of acetic acid with ammonium carbonate or by saturating glacial acetic acid with ammonia.[11] Obtaining crystalline ammonium acetate is difficult on account of its hygroscopic nature.

References

  1. ^ a b c Pradyot, Patnaik (2003). Handbook of Inorganic Chemicals. The McGraw-Hill Companies, Inc. ISBN 0-07-049439-8.
  2. ^ a b c d e "Ammonium acetate".
  3. ^ a b c d "Safety Data Sheet of Ammonium Acetate" (PDF). tedia.com. Tedia Company Inc. 2011-08-12. Retrieved 2014-06-10.
  4. ^ 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.
  5. ^ a b 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. ISBN 978-3527306732.
  6. ^ "Spirit of Mindererus". TheFreeDictionary.com. Retrieved 2023-06-07.
  7. ^ Coleman, G. H.; Alvarado, A. M. (1923). "Acetamide". Organic Syntheses. 3: 3; Collected Volumes, vol. 1, p. 3.
  8. ^ 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 (8): 1230–1236. doi:10.1016/j.jasms.2008.05.006. PMID 18565760.
  9. ^ Konermann, Lars (2017). "Addressing a Common Misconception: Ammonium Acetate as Neutral pH "Buffer" for Native Electrospray Mass Spectrometry". American Society for Mass Spectrometry. 28 (9): 1827–1835. Bibcode:2017JASMS..28.1827K. doi:10.1007/s13361-017-1739-3. PMID 28710594. S2CID 25294943. Retrieved 25 October 2022.
  10. ^ Australia New Zealand Food Standards Code "Standard 1.2.4 - Labelling of ingredients". Retrieved 2011-10-27.
  11. ^ Brannt, William (1914). A practical treatise on the manufacture of vinegar. Lancaster, PA: Henry Carey Baird & Co. pp. 316–317.
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