Chemistry Reference
In-Depth Information
ACIDS
Common acids:
O
OO
OH
O
CH
3
COH
HO
C(CH
2
)
4
C
HC
OH
formic acid
acetic acid
adipic acid
Manufacture:
Air
C
H
3
CHO
+
CH
3
COOH
acetaldehyde
acetic acid
CH
3
OH
+
CO
CH
3
COOH
methanol
acetic acid
H
H
O
+
+
O
2
HNO
3
HOOC(CH
2
)
4
COOH
cyclohexane
cyclohexanol
cyclohexanone
adipic acid
Organic acids, known as carboxylic acids, contain the carboxyl group,
COOH. They behave as acids, CH
3
COOH
H
+
in water and
form salts when reacted with an alkaline or basic material such as sodium
hydroxide. In salt formation, the hydrogen of the
CH
3
COO
−
+
OH group is replaced by
a cation. Most carboxylic acids give a weak acid response in water, but some
(e.g., Cl
3
C
−
COOH) approach the acidity of inorganic acids.
Carboxylic acids with one acid group are known as
monobasic
acids
while those with two acid groups are
dibasic
acids. All acids with more than
one acid group are in the class of
polybasic
acids. The simplest organic acid,
formic acid, is responsible for the irritation of bee and ant stings. Vinegar is
a 5% solution of acetic acid in water. The acetic acid is responsible for the
characteristic sour taste. Citric acid, found in citrus fruits and used in soft
drinks, is a tribasic acid with three carboxylic acid groups. The dibasic acid,
adipic acid, is a major component of nylon.
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