(organic chemistry) A saturated fatty acid, CH₃(CH₂)₁₅COOH, that occurs only in very small amounts in natural oils and fats

(chemistry) an anhydrous form of phosphoric acid that exists as a polymeric glassy solid, (HPO₃)ₙ; used as a drying agent and in dental cement

(organic chemistry) An polyunsaturated fatty acid, having 18 carbon atoms and three double bonds, essential for human nutrition; it is found in linseed and other vegetable oils

(organic chemistry) A colourless liquid, an unsaturated organic acid, used in the manufacture of resins and plastics, with the chemical formula CH₂:C(CH₃)COOH.

(biochemistry) pyridine-3-carboxylic acid; together with nicotinamide is a part of the vitamin B complex

(organic chemistry) A saturated fatty acid, CH₃(CH₂)₁₂COOH, tetradecanoic acid, found in both animal and vegetable oils and fats; used in the manufacture of soap, cosmetics etc.

(obsolete, inorganic chemistry) Hydrochloric acid. / A low grade, industrial grade or impure form of hydrochloric acid, often containing traces of iron.

(organic chemistry) An unsaturated fatty acid cis-6-octadecenoic acid found in many members of the family Apiaceae (e.g. parsley seed oil); it is a positional isomer of oleic acid, the double bond being in position 6 instead of 9.

(chemistry) A supposed acid formed from osmium tetroxide but known only as osmate salts.

(inorganic chemistry) A weak acid, HNO₂, known only in solution, or as its salts and esters, the nitrites; it has a linear structure, H-O-N=O