Ammonium acetate
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| Ammonium acetate | |
| General | |
|---|---|
| Chemical formula | CH3COONH4 |
| Appearance | white solid |
| CAS number | 631-61-8 |
| Physical | |
| Molecular weight | 77.0825g amu |
| Melting point | 385°K (112°C) |
| Boiling point | n/a |
| Density | 1.07 g/cm³ |
| Crystal structure | orthorhombic |
| Solubility | 148 g/100 g of water (4°C) |
| Thermochemistry | |
| ΔfH0gas | ? |
| ΔfH0liquid | ? |
| ΔfH0solid | -616.14 kJ/mol |
| S0gas, 1 bar | ? |
| S0liquid, 1 bar | ? |
| S0solid | ? |
| Safety | |
| Ingestion | Large doses may cause abdominal pain, nausea and vomiting. |
| Inhalation | May cause irritation, with symptoms of coughing, sore throat, labored breathing, and chest pain. |
| Skin | May cause irritation (redness and/or pain). |
| Eyes | Chronic exposure may cause irritation, redness and pain. |
|
SI units and standard conditions used unless otherwise stated. | |
Ammonium acetate is CH3COONH4. This salt is derived from the reaction of ammonia and acetic acid.
- CH3COOH + NH3 → CH3COONH4
It is widely available commercially.
Contents |
[edit] Uses and distinctive properties
As the salt of a weak acid and a weak base, ammonium acetate has a number of distinctive properties.
- CH3COONH4 is occasionally employed as a biodegradable de-icing agent.
- It is often used with acetic acid to create an buffer solution, one that can be thermally decomposed to non-ionic products
- Ammonium acetate is useful in the Knoevenagel condensation in organic synthesis.
- It is relatively unusual example of a salt that melts at low temperatures.
[edit] Properties
CH3COONH4 is hygroscopic. It decomposes easily at elevated temperatures into acetamide.
- CH3COONH4 → CH3C(O)NH2 + H2O
In this reaction, a salt is converted to two molecular species, which is a relatively uncommon conversion at mild temperatures.
[edit] Home synthesis
At home it can be made by reacting ammonia solution with dilute acetic acid and evaporating the water. The possibility of thermal decomposition means that the water must be removed without raising the temperature. The removal of water may be sped up by conducting the evaporation under vacuum, and should be carried out until dry.
[edit] References
G. Jones Organic Reactions, 1967, volume 15, 204ff (the Knoevenagel Reaction)
