The first thing to do in order to get to know the term anhydride is to discover its etymological origin. In this case, we can say that it comes to be a word of Greek origin that can be translated as “that has the aspect of not having water”. It is a word that was formed from the sum of the following elements:
-The prefix “an-“, which is equivalent to “without”.
-The noun “hydros”, which is synonymous with “water”.
-The suffix “-ido”, which can be determined to mean “that has appearance”.
The term anhydride can also be emphasized as anhydride. The concept is used in the field of chemistry to name the compound that is formed with a non-metal and oxygen and that, when it reacts with water, generates an acid.
Anhydrides are also called non-metallic oxides or acidic oxides. These are binary-type chemical compounds that arise when a non-metallic element is combined with oxygen.
An example of anhydride is carbon dioxide or carbon dioxide. This oxide has molecules made up of two oxygen atoms and a carbon atom (the non-metallic element), which are linked by double covalent bonds. When carbon dioxide reacts with water, it becomes an oxyacid acid known as carbonic acid.
The sulfur dioxide or sulfur dioxide is another anhydride. In this case, the chemical compound has one sulfur atom and two oxygen atoms. Sulfur is the non-metallic element; As for the result of the reaction of this anhydride with water, it is called sulfurous acid.
Regarding the anhydride nomenclature, you can choose the traditional nomenclature (the name begins with the word “anhydride” and then it is completed according to the oxidation states), the systemic nomenclature (depends on the number of atoms) and the Stocke nomenclature (It begins with “oxide”, continues with the name of the element and ends with the oxidation state in Roman numerals and in parentheses).
In the same way, we cannot forget what is called acid anhydrides, of which the following particularities can be highlighted:
-They are also called carboxylic anhydrides.
-They come from the dehydration of two molecules, or at least one in the intramolecular case, of carboxylic acid.
-They have the particularity that they are considered to be especially reactive.
-There are different types, especially those called mixed and symmetrical.
-It is established that when carrying out its nomenclature they will be called as the acids of origin with the exception that the word anhydride will be established in front of them.
-Although they can be used in different areas, as a general rule, where they have the most value and presence is in the manufacture of medicines. Exactly by using this type of acid anhydrides, for example, the preparation of what is the drug commonly known as acetylsalicylic acid is undertaken.