… acid constitute plastics (Chapter 39). (3) Oleic acid (C 18 H 34 O 2 ). Found in fats and oils as a glyceride. A … remain classified in this heading. (4) Linoleic acid (C 18 H 32 O 2 ). Contained in linseed oil as a glyceride; a drying acid. (5) Linolenic acid (C 18 H 30 O 2 ). (6) Heptynoic and octynoic acids. (B) …