What Is an Acid Anhydride?
Anhydrides (English: Anhydrides) is the remaining part of a certain oxygen-containing acid to remove one or several molecules of water. Generally, an inorganic acid is one molecule of the acid, and an acid anhydride is formed by directly losing one molecule of water, and the valence of an acid-determining element in the acid anhydride is unchanged. The organic acid is formed by two molecules of the acid or multiple molecules of the acid through an intermolecular dehydration reaction. Only oxyacids have anhydrides. Anaerobic acid is free of acid anhydride.
- "Anhydride is
- Theoretically, acid anhydride and
Acetic anhydride
- A compound formed by acid shrinking water, for example, a carbonic acid molecule (H 2 CO 3 ) and a molecule of water (H 2 O) remaining carbon dioxide (CO 2 ) is carbonic anhydride. Two vinegar molecules (CH 3 COOH) shrink one molecule of water (H 2 O) and the rest ((CH 3 CO) 2 O) is acetic anhydride.
- Acetic anhydride is not an oxide.
Acid anhydride
- Silicic acid anhydride: silicon dioxide (SiO 2 ).
- Silica does not react with water, that is, it does not generate silicic acid in contact with water, but silica is artificially defined as an anhydride of silicic acid.
Permanganic anhydride
- Permanganic anhydride: manganese hexaoxide (Mn 2 O 7 )
- KMnO 4 (potassium permanganate) and cold concentrated sulfuric acid produce dark green oily manganese hexaoxide (Mn 2 O 7 ):
- 5H 2 SO 4 + 4KMnO 4 2K 2 SO 4 + Mn 2 (SO 4 ) 3 + Mn 2 O 7 + 5H 2 O + 2O 2
- When it encounters organic matter, it will burn, decompose by thermal explosion, and slowly release O 2 (oxygen) to MnO 2 (manganese dioxide) at room temperature, and a small amount of ozone will be generated during decomposition.