Acetaldehyde
Description
A colorless, volatile liquid with a characteristic fruity odor. Acetaldehyde reacts as a reducing agent when mixed with Tollen's reagent (ammonia - Silver nitrate) to form metallic silver on mirrors. It is used in the manufacture of paraldehyde, perfumes, flavors, aniline dyes, plastics, synthetic rubber, explosives. Acetaldehyde is also used to harden gelatin fibers and as a preservative and flavoring agent in foods and beverages.
Acetaldehyde is an aerosol Pollutant in outdoor, as well as, indoor environments. Additionally, its use in industry is widespread where it may be released into waste water or the air. As acetaldehyde is a precursor of Acetic acid, the potential to damage museum objects is high.
- See Pollutant record for a comparison table of aerosols and collection risks.
Synonyms and Related Terms
ethanal (IUPAC); acetic aldehyde; aldehyde; ethyanal; ethyl aldehyde
Personal Risks
- Flammable, explosion risk, suspected carcinogen.
- Irritating to skin, eye and throat with the potential to cause burns and dermatitis.
- ThermoFisher: SDS
Collection Risks
- Metal corrosion
- Cellulose and protein embrittlement
- Degradation of soda-rich glass, enamels, and pigments
Physical and Chemical Properties
Miscible with water, ethanol, ether, benzene, gasoline, solvent naphtha, toluene, xylene, turpentine, acetone.
| Composition | CH2CHO |
|---|---|
| CAS | 75-07-0 |
| Melting Point | -123.5 C |
| Density | 0.788 g/ml |
| Molecular Weight | mol. wt. = 44.05 |
| Refractive Index | 1.379 |
| Boiling Point | 21 C |
Resources and Citations
- Wikipedia: Acetaldehyde Accessed July 2023
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- ASTM, Standard Terminology Relating to Conditioning, Annual Book of ASTM Standards, Section 6, Paints, Related Coatings and Aromatics, ASTM, E41, 23-24, Sep-92
- The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
- CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: ref. index=1.379