A solvent is a liquid (gas, or solid) that can dissolve solid, liquid, or gaseous solutes (both solvents and solutes can be solid, liquid, or gas), and then become a solution. The most common solvent in daily life is water. The so-called organic solvent refers to organic compounds containing carbon atoms. Solvents usually have a relatively low boiling point and are easily volatile. Alternatively, it can be removed by distillation, leaving behind the dissolved substance. Therefore, solvents cannot react chemically with solutes. They must be inert. Solvents can extract soluble compounds from mixtures, a common example being brewing coffee or tea with hot water. Solvents are usually transparent, colorless liquids, and most of them have a unique odor

There are a wide variety of chemical reagents, and there is no unified international classification method.

. Most countries are divided into several to dozens of categories based on their application scope, such as general reagents, analytical reagents, standard reagents, clinical chemical reagents, and electronic industry reagents. Each category can also be divided into several subcategories