Ammonium acetate

Ammonium acetate

Names
IUPAC name Ammonium ethanoate
Systematic IUPAC name Ammonium acetate
Other names Azanium acetate
Identifiers
Jmol-3D images	Image
SMILES O=C(O)C.N
Properties
Chemical formula	CH3COONH4 C2H7NO2
Molar mass	77.08 g/mol
Appearance	Deliquescent white solid
Odor	Acetic
Melting point	110–114 °C (230–237 °F; 383–387 K) (Decomposes)
Boiling point	117.1 °C (242.8 °F; 390.2 K) (At 760 mmHg, decomposes)
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	Reacts with strong acids Soluble in acetone, ammonia, ethanol, sulfur dioxide
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
Thermochemistry
Std enthalpy of formation (ΔfHo298)	−615 kJ/mol
Hazards
Safety data sheet	ScienceLab
Flash point	136 °C
Lethal dose or concentration (LD, LC):
LD50 (Median dose)	386 mg/kg (mice, intravenous)
Related compounds
Related compounds	Ammonium formate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Ammonium acetate is a chemical compound with the formula NH₄CH₃COO (sometimes written as CH₃COONH₄).

Properties

Chemical

Ammonium acetate decomposes at temperatures above 165 °C to yield acetamide:

CH₃COONH₄ → CH₃C(O)NH₂ + H₂O

If acetamide is heated further, in the presence of a drying agent, it will convert to acetonitrile (methyl cyanide).

Physical

Ammonium acetate is a white hygroscopic solid. Ammonium acetate is volatile at low pressures and has a vinegar-like smell.

Availability

Ammonium acetate can be purchased online cheaply.

Preparation

Ammonium acetate can be prepared by reacting acetic acid with ammonia, ammonium bicarbonate or carbonate. Drying the solution by boiling the excess water is difficult, as ammonium acetate will decompose. Heating the solution on a water bath at below 90 °C is an option, though a bit of ammonium acetate will decompose, causing the solution to darken. This isn't much of a problem, as the contamination will not precipitate when recrystallizing the acetate from the solution, and can be removed by vacuum filtering the crystals and wash them with cold water or acetone.

The best way to synthesize ammonium acetate, with insignificant product loss, is to bubble ammonia gas into anhydrous (glacial) acetic acid, which causes the ammonium acetate to crystallize and crash out of the acetic acid. Filter the wet crystals and sir dry them. While attractive, this method relies on using gaseous ammonia which means you'll need a more complicated system, than simply dumping an ammonium salt in acetic acid.

Projects

• Acetamide synthesis
• Acetonitrile synthesis

Handling

Safety

Ammonium acetate is non-toxic, though if heated it can generate acetamide which is considered carcinogenic.

Ammonium acetate is hygroscopic and will slowly hydrolyze to yield acetic acid, which is irritant and corrosive in large quantities.

Storage

Ammonium acetate should be stored in dry sealed containers, as it's hygroscopic.

Disposal

Ammonium acetate is a harmless source of nitrogen to organic life and can be discarded without any special treatments.

References

Relevant Sciencemadness threads

• Ammonium acetate
• blood red ammonium acetate.
• Ammonium Acetate