Ammonium acetate

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Ammonium acetate
Ammonium acetate skeletal formula Ammonium-acetate-2D.png
Ammonium acetate skeletal formula
Ball-and-stick model of ammonium acetate Ammonium-acetate-3D-balls.png
Ball-and-stick model of ammonium acetate
Crystalline of ammonium acetate Ammonium-acetate.JPG
Crystalline of ammonium acetate
Names
IUPAC name
Ammonium ethanoate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.010.149 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 211-162-9
PubChem CID
RTECS number
  • AF3675000
UNII
UN number 3077
  • InChI=1S/C2H4O2.H3N/c1-2(3)4;/h1H3,(H,3,4);1H3 Yes check.svgY
    Key: USFZMSVCRYTOJT-UHFFFAOYSA-N Yes check.svgY
  • 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
AppearanceWhite 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) [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
Occupational safety and health (OHS/OSH):
Main hazards
Irritant
GHS labelling: [4]
GHS-pictogram-exclam.svg
Warning
H303, H316, H320, H333
P281, P335
NFPA 704 (fire diamond)
[4]
NFPA 704.svgHealth 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) [4]
Lethal dose or concentration (LD, LC):
386 mg/kg (mice, intravenous) [3]
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).
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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]

Contents

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

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. 1 2 3 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. 1 2 3 4 5 "Ammonium acetate".
  4. 1 2 3 4 "Safety Data Sheet of Ammonium Acetate" (PDF). tedia.com. Tedia Company Inc. 2011-08-12. Retrieved 2014-06-10.
  5. 1 2 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   978-3-527-30673-2.
  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.