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. It is commonly used in biochemistry and molecular biology as a buffer in various applications, such as protein purification and chromatography.
Properties
Ammonium acetate is highly soluble in water. Its solubility in water at room temperature is approximately 148 g/100 mL. In aqueous solution, it is slightly acidic. The pH of a 0.1 M solution is around 7. It has a slight ammonia odor due to the presence of the ammonium ion. It is stable under normal conditions but can decompose when heated to produce ammonia and acetic acid.
- 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); 1.073 g/cm3 (25 °C)
- Melting point: 113 °C (235 °F; 386 K)[4]
- Solubility in water: 102 g/100 mL (0 °C); 148 g/100 mL (4 °C), 143 g/100 mL (20 °C); 533 g/100 mL (80 °C)
- Solubility: Soluble in alcohol, SO2, acetone, liquid ammonia
- Solubility in methanol: 7.89 g/100 mL (15 °C); 131.24 g/100 g (94.2 °C)
- Solubility in dimethylformamide: 0.1 g/100 g
Production
Ammonium acetate is produced by the neutralization of acetic acid with ammonium carbonate or by saturating glacial acetic acid with ammonia. Obtaining crystalline ammonium acetate is difficult on account of its hygroscopic nature.
History
The synonym Spirit of Mindererus is named after R. Minderer, a physician from Augsburg.
Uses
It is the main precursor to acetamide: NH4CH3CO2 → CH3C(O)NH2 + H2O
Ammonium acetate is also used in the preparation of other ammonium salts, as a food additive (E260), and in some pharmaceutical formulations. It is relatively inexpensive and has low toxicity compared to many other salts, making it a preferred choice in certain applications.
