formic acid or methanoic acid, HCO₂H, a colorless, corrosive liquid with a sharp odor; it boils at 100.7°C; and solidifies at 8.4°C;. It has the lowest molecular weight and is the simplest of the carboxylic acids. Functionally, it is both an acid and an aldehyde. Like other acids, it reacts with most alcohols to form esters and decomposes when heated; like other aldehydes, it is easily oxidized. Formic acid occurs in the bodies of red ants and in the stingers of bees. It can be made by the oxidation of formaldehyde; it is prepared commercially by heating carbon monoxide and sodium hydroxide to form sodium formate which, when carefully treated with sulfuric acid, yields formic acid. Formic acid is used industrially in textile dyeing, in leather tanning, and in coagulating latex rubber.

Simplest carboxylic acid, chemical formula HCOOH. It is secreted by some insects, especially red ants (its name comes from the Latin word for ant), in their bite or sting. It has many industrial uses, in textile and leather manufacture, as an industrial solvent, and as an intermediate.

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