Acetaldehyde
. Acetaldehyde, volatile, colorless, liquid, with a pungent, fruity odor. It is important as an intermediate in the manufacture of many chemicals, pharmaceuticals , and plastics , including acetic acid , butyl alcohol , chloral, and pyridine. Acetaldehyde is miscible (mixable) in all proportions with water and most common organic solvents and is manufactured by the oxidation of ethylene , by the oxidation of ethyl alcohol , or by the combination of water with acetylene . Acetaldehyde melts at -123.5° C (-190.3° F), boils at 20.8° C (69.4° F), and has a density of 0.778 g per ml at 20° C (68° F).