Chlorobenzenes

Part of speech: noun

Definitions

1. Aromatic compounds in which one or more chlorine atoms are attached to a benzene ring, used as solvents and chemical intermediates
2. Organic chemical compounds made of a benzene ring bonded to chlorine atoms, employed in manufacturing and as industrial solvents
3. Chlorine-substituted derivatives of benzene that form a family of industrially important aromatic chemicals and solvents

Etymology: Chlorobenzenes are a family of compounds, not a single substance: benzene rings in which one or more hydrogen atoms have been replaced by chlorine atoms. The plural simply counts the members of that family, so the word is the plural of "chlorobenzene," which is a compound name built from two older words stuck together. The first part, "chloro-," comes from the Ancient Greek "khlōrós," meaning pale green or yellowish-green, the same root that gave English "chlorine." Chlorine was named for the colour of its gas. The second part, "benzene," takes its name from "benzoe," a German form of "benjoin" (benzoin), a resin that was the original source of the compound. Benzene was first isolated from that resin, and its name passed through German "Benzin" into English as "benzine" before settling as "benzene." Joining the two parts gives a precise chemical label: a chlorine (the pale-green element) attached to a benzene ring. The plural form, "chlorobenzenes," refers to the group of molecules that carry one or more chlorine atoms on that ring.