O_{2} (H_{2}SO_{4}) + NaOH = SO_{2} (NaH_{2}SO_{4}) + H_{2}O
\ \
OH OH

Sulfuric Acid Acid sodium sulfate

OH ONa
/ /
or, SO_{2} (H_{2}SO_{4}) + 2NaOH = SO_{2} (Na_{2}SO_{4}) + 2H_{2}O
\ \
OH ONa

Sulfuric Acid Neutral sodium sulfate

Similarly, with oxalic acid:

COOH COOK
| (H_{2}C_{2}O_{4}) + KOH = | + H_{2}O
COOH COOH

Oxalic acid Acid potassium oxalate

or, COOH COOK
| (H_{2}C_{2}O_{4}) + 2KOH = | + 2H_{2}O
COOH COOK

Oxalic acid Neutral potassium oxalate

Similarly, the acid H atom of either an organic or an inorganic acid may be
replaced by the alkyl group of an alcohol, producing "ethereal salts," or
"esters."

Thus, with nitric acid;

NO_{2}OH(HNO_{3})+C_{2}H_{5}OH = NO_{2}OC_{2}H_5(C_{2}H_{5}NO_{3})+H_{2}O

Nitric acid Ethyl alcohol Ethyl nitrate

And, with acetic acid;

CH_{3}.COOH(H_{4}C_{2}O_{2})+C_{2}H_{5}OH = CH_{3}.COOC_{2}H_{5}+H_{2}O

Acetic acid Ethyl acetate

With dibasic or polybasic acids, either one or more of the carboxyl H atoms
may be replaced with an alcohol radical, so that both acid and neutral
esters of all such acids are possible. Examples of all of these different
types of derivatives of organic acids are frequently found in plant
tissues.

The occurrence, properties, and functions of a particular type of glycerol,
and other esters of organic acids, which are known as fats and waxes, are
not taken into consideration in the following discussions, but reserved for
a subsequent chapter dealing specially with them.

SOME COMMON ORGANIC ACIDS

Free organic acids, or their mineral salts or volatile esters, sometimes
occur as separate and characteristic individual compounds in particular
species of plants, or fruits; but much more commonly, two, three, or even
more acids or their derivatives, are associated together.

=Formic acid=, H.COOH (H_{2}CO_{2}), occurs in free form