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Names | |
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IUPAC name Ammonium ethanoate | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.010.149 |
EC Number |
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PubChem CID | |
RTECS number |
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UNII | |
UN number | 3077 |
CompTox Dashboard (EPA) | |
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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) [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 | |
Std enthalpy of formation (ΔfH⦵298) | −615 kJ/mol [3] |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards | Irritant |
GHS labelling: [4] | |
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Warning | |
H303, H316, H320, H333 | |
P281, P335 | |
NFPA 704 (fire diamond) | |
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). |
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]
The synonym Spirit of Mindererus is named after R. Minderer, a physician from Augsburg. [6]
It is the main precursor to acetamide: [7]
It is also used as a diuretic. [5]
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]
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]
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.