Anhydrides

Part of speech: noun

Definitions

1. Compounds derived from acids through the elimination of water in a dehydrating process
2. Chemicals that form when water is removed from acids, resulting in new reactive phases
3. Molecules created when water is removed from acids, producing a new chemical species

Etymology: The word is a noun formed from two parts. Its first half, "an-", is the Ancient Greek prefix meaning "without" or "not," the same element that appears in "anarchy" and "anaerobic." The second half is "hydride," itself built from "hydro-," the combining form of the Greek "hydor," meaning "water," plus the chemical suffix "-ide." Put together, the name describes a compound stripped of water. That literal sense is the key to the chemistry. An anhydride is what remains when water is removed from an acid, so the name is essentially a description of the process: an acid without its water. The prefix "an-" also appears in "anhydrous," which describes substances containing no water, and the two words share the same logic.