Anhydride

Acid anhydrides can generally be regarded as oxides formed by dehydration of acids (the anhydrides of organic acids are not oxides), and many of them can react with water to form the original acid. According to the properties of the acid, it can be divided into inorganic acid anhydrides (formed by the shrinkage of one or two acid molecules) and organic acid anhydrides (compounds formed by the shrinkage of two monobasic acid molecules or one dibasic acid molecule).