Anhydrides
An anhydride (from the Greek án (h) ydros " waterless ", " anhydrous ") is a chemical compound that is created from an acid or base by removing water .
For example, carbon dioxide is the anhydride of the very unstable carbonic acid .
- Non-metal oxides such as sulfur trioxide or phosphorus (V) oxide are acid anhydrides .
- Metal oxides such as calcium oxide are known as base anhydrides .
- Anhydrides, which are formed from two carboxylic acid molecules by splitting off a water molecule, are called carboxylic acid anhydrides in chemistry .
- Maleic anhydride is a cyclic carboxylic acid anhydride that is produced by splitting off water from maleic acid (a dicarboxylic acid).
- Substances free of water of crystallization (e.g. minerals ), on the other hand, are referred to as anhydrate .