Chemistry Reference
In-Depth Information
ALDEHYDES
Common aldehydes:
O
O
O
CH
3
CH
CH
3
CH
2
CH
HCH
formaldehyde
acetaldehyde
propionaldehyde
Manufacture:
CH
3
OH
+
Air
HCHO
+ H
2
O
methanol
formaldehyde
CH CH
+
H
2
O
CH
3
CHO
=
acetylene
acetaldehyde
CH
2
=CH
2
+Air
CH
3
CHO
ethylene
acetaldehyde
Aldehydes are characterized by a carbonyl group (
O) at the end of a
chain with the carbon of the carbonyl group also bonded to a hydrogen.
Aldehydes can be considered to be a dehydrogenated (loss of hydrogen) or
oxidized alcohol; for example formaldehyde is formed by the partial oxida-
tion of methanol as shown above and acetaldehyde is formed by the partial
oxidation of ethanol. Formaldehyde is a gas and is important as a fumigant.
Dissolved in water, it (formalin) is used as a germicide, perservative, and
embalming agent. It is also a widely used intermediate in the manufacture
of certain plastics and adhesives. Acetaldehyde, a liquid, is an intermediate
in the manufacture of acetic acid and acetic anhydride, both important indus-
trial chemicals.
−
C
=
