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
CAS Number	631-61-8  Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:62947  N
ChemSpider	11925  Y
ECHA InfoCard	100.010.149
EC Number	211-162-9
PubChem CID	517165
RTECS number	AF3675000
UNII	RRE756S6Q2  Y
UN number	3077
CompTox Dashboard (EPA)	DTXSID5023873
InChI InChI=1S/C2H4O2.H3N/c1-2(3)4;/h1H3,(H,3,4);1H3 Y Key: USFZMSVCRYTOJT-UHFFFAOYSA-N Y InChI=1/C2H4O2.H3N/c1-2(3)4;/h1H3,(H,3,4);1H3 Key: USFZMSVCRYTOJT-UHFFFAOYAY
SMILES O=C([O-])C.[N+H4]
Properties
Chemical formula	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) [2]
Solubility in water	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
Magnetic susceptibility (χ)	−41.1·10−6 cm3/mol
Viscosity	21
Structure
Crystal structure	Orthorhombic
Thermochemistry
Std enthalpy of formation (ΔfH⦵298)	−615 kJ/mol [3]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Irritant
GHS labelling: [4]
Pictograms
Signal word	Warning
Hazard statements	H303, H316, H320, H333
Precautionary statements	P281, P335
NFPA 704 (fire diamond)	[4] 1 1 1
Flash point	136 °C (277 °F; 409 K) [4]
Lethal dose or concentration (LD, LC):
LD50 (median dose)	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). N  verify  (what is  YN ?) Infobox references

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 (ammonium) and a weak base (acetate), is often used 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. 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. "Ammonium acetate".
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. 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.