(chemistry) a solution of hydrogen iodide, HI, in water; it is a strong acid and reducing agent

(chemistry) an alternative name for hyposulfurous acid

(chemistry) A solution of hydrogen fluoride, HF, in water; it is a weak but very corrosive acid, used in the production of fluorine compounds, and in metallurgy.

(organic chemistry) The simplest carboxylic acid, HCOOH, a colourless, corrosive liquid with a sharp odour; it is present in the stings of ants, bees and nettles, and is prepared industrially by the oxidation of methanol or formaldehyde; it has some industrial uses, and its esters, the formates are used in perfumes.

(organic chemistry) A saturated fatty acid, CH₃(CH₂)₁₀COOH, occurring in coconut, palm and laurel oil; mostly used in making cosmetics and soaps

(chemistry) a solution of hydrogen cyanide, HCN, in water; a weak poisonous acid, used as a fumigant

(chemistry) a yellowish hygroscopic solid, H₃PO₃; a mild reducing agent

(biochemistry) one of the constituents of the citric acid cycle, formed by the oxidation of malic acid and via the transamination of aspartic acid; an intermediate in the synthesis of amino acids and the metabolism of carbohydrates

(chemistry) a carboxylic acid derived from galactose by oxidation of the terminal CH₂OH to a COOH; it polymerizes to form pectic acid

(chemistry) the acid, HMnO₄, known only as its salts, the permanganates