Subject - General Chemistry

The process to remove water from a chemical compound is called dehydration.

In general, dehydration (elimination of $\text{H}$ and $\text{O}\text{H}$) is an intramolecular reaction which can be carried out using a variety of reagents, such as acids, oxidic catalysts or enzymes. In industry, important dehydration reactions are the formation of alkenes from alcohols (β-elimination), anhydrides from dicarboxylic acids, nitriles from amides, and lactones from hydroxycarboxylic acids. Intermolecular dehydration (elimination of $\text{H}$ and $\text{O}\text{H}$ from two different molecules) yields ethers from alcohols and peptides from amino acids, for example.

Sometimes, the term dehydration is used for freeze-drying of food and removal of water from crystalline hydrates.