KeywordsAcetic Acid Melting Point Organic Compound Bioorganic Chemistry Boiling Point
Acetaldehyde is an organic compound with the chemical formula CH3CHO Open image in new window . It is the smallest aldehyde after formaldehyde. It is a colorless liquid at room temperature with an irritating odor. It can be obtained by the oxidation of ethanol or by the reduction of acetic acid. When we drink alcohol, the ethanol is oxidized to acetaldehyde, by alcohol dehydrogenase, which is then oxidized to acetic acid by aldehyde dehydrogenase in the liver. It can be formed easily from gas mixtures containing methane by ultraviolet light and electric discharges, among others. It reacts with hydrogen cyanide and ammonia to give 2-aminopropionitrile, which gives alanine (amino acid) after hydrolysis. It has been detected in extracts from carbonaceous chondrites. Melting point: −123.5 °C, boiling point: −20.2 °C, density: 0.788 g cm −3.