Ammonium acetate

From Wikipedia, the free encyclopedia - View original article

Ammonium acetate
Ammonium acetate skeletal formula
Ball-and-stick model of ammonium acetate
Crystalline of ammonium acetate
Identifiers
CAS number631-61-8 YesY
PubChem517165
ChemSpider11925 YesY
UNIIRRE756S6Q2 YesY
ChEBICHEBI:62947 N
RTECS numberAF3675000
Jmol-3D imagesImage 1
Properties
Molecular formulaC2H7NO2
Molar mass77.08 g mol−1
AppearanceWhite solid crystals, deliquescent
OdorSlighty acetic
Density1.17 g/cm3 (20 °C)[1]
1.073 g/cm3 (25 °C)
Melting point110–114 °C (230–237 °F; 383–387 K) [3][1]
decomposes[2]
Boiling point117.1 °C (242.8 °F; 390.2 K)
at 760 mmHg, decomposes
Solubility in water102 g/100 mL (0 °C)
148 g/100 mL (4 °C)[1]
143 g/100 mL (20 °C)
533 g/100 mL (80 °C)
SolubilitySoluble in alcohol, SO2, acetone, liquid ammonia[2]
Solubility in methanol7.89 g/100 mL (15 °C)[3][1]
131.24 g/100 g (94.2 °C)[2]
Solubility in dimethylformamide0.1 g/100 g[2]
Structure
Crystal structureOrthorhombic
Thermochemistry
Std enthalpy of
formation
ΔfHo298
−615 kJ/mol[2]
Hazards
MSDSJT Baker
GHS pictogramsThe exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)[3]
GHS signal wordWarning
GHS hazard statementsH303, H316, H320, H333[3]
GHS precautionary statementsP281, P335[3]
Main hazardsIrritant
NFPA 704
Flash point136 °C (277 °F; 409 K) [3]
LD50386 mg/kg (mice, intravenous)[2]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references
 
Jump to: navigation, search
Ammonium acetate
Ammonium acetate skeletal formula
Ball-and-stick model of ammonium acetate
Crystalline of ammonium acetate
Identifiers
CAS number631-61-8 YesY
PubChem517165
ChemSpider11925 YesY
UNIIRRE756S6Q2 YesY
ChEBICHEBI:62947 N
RTECS numberAF3675000
Jmol-3D imagesImage 1
Properties
Molecular formulaC2H7NO2
Molar mass77.08 g mol−1
AppearanceWhite solid crystals, deliquescent
OdorSlighty acetic
Density1.17 g/cm3 (20 °C)[1]
1.073 g/cm3 (25 °C)
Melting point110–114 °C (230–237 °F; 383–387 K) [3][1]
decomposes[2]
Boiling point117.1 °C (242.8 °F; 390.2 K)
at 760 mmHg, decomposes
Solubility in water102 g/100 mL (0 °C)
148 g/100 mL (4 °C)[1]
143 g/100 mL (20 °C)
533 g/100 mL (80 °C)
SolubilitySoluble in alcohol, SO2, acetone, liquid ammonia[2]
Solubility in methanol7.89 g/100 mL (15 °C)[3][1]
131.24 g/100 g (94.2 °C)[2]
Solubility in dimethylformamide0.1 g/100 g[2]
Structure
Crystal structureOrthorhombic
Thermochemistry
Std enthalpy of
formation
ΔfHo298
−615 kJ/mol[2]
Hazards
MSDSJT Baker
GHS pictogramsThe exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)[3]
GHS signal wordWarning
GHS hazard statementsH303, H316, H320, H333[3]
GHS precautionary statementsP281, P335[3]
Main hazardsIrritant
NFPA 704
Flash point136 °C (277 °F; 409 K) [3]
LD50386 mg/kg (mice, intravenous)[2]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Ammonium acetate is a chemical compound with the formula NH4C2H3O2 (or C2H4O2.NH3 or C2H7NO2). It is a white solid and can be derived from the reaction of ammonia and acetic acid. It is available commercially and, depending on grade, can be rather inexpensive.

Uses and distinctive properties[edit]

As the salt of a weak acid and a weak base, ammonium acetate has a number of distinctive properties.

Ammonium acetate is volatile at low pressures. Because of this, it has been used to replace cell buffers with non-volatile salts in preparing samples for mass spectrometry.[4] It is also popular as a buffer for mobile phases for HPLC with ELSD detection for this reason. Other volatile salts that have been used for this include ammonium formate.

Food Additive[edit]

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.[5]

Properties[edit]

CH3COONH4 is hygroscopic and decomposes easily to acetamide if heated above 165 °C.[citation needed]

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. Further dehydration leads to acetonitrile or methyl cyanide, an important and widely used solvent.

Production[edit]

Ammonium acetate is produced by the neutralization of acetic acid with ammonium carbonate or by saturating glacial acetic acid with dry ammonia gas.[6] Obtaining crystalline ammonium acetate is difficult on account of its aqueous solution giving off ammonia when evaporated.

References[edit]

  1. ^ a b c d Pradyot, Patnaik (2003). Handbook of Inorganic Chemicals. The McGraw-Hill Companies, Inc. ISBN 0-07-049439-8. 
  2. ^ a b c d e f http://chemister.ru/Database/properties-en.php?dbid=1&id=354
  3. ^ a b c d e f g "Safety Data Sheet of Ammonium Acetate". http://www.tedia.com. Tedia Company Inc. 2011-08-12. Retrieved 2014-06-10. 
  4. ^ Berman et al., 2008. J Am Soc Mass Spectrom, 19:1230-1236.
  5. ^ Australia New Zealand Food Standards Code "Standard 1.2.4 - Labelling of ingredients". Retrieved 2011-10-27. 
  6. ^ Brannt, William (1914). A practical treatise on the manufacture of vinegar. Lancaster, PA: Henry Carey Baird & Co. pp. 316–317. 

Further reading[edit]

External links[edit]