Chromium and its compounds play an important role in the fields of industry, chemistry and materials science. The following are the main functions and applications of chromium compounds: 1. Catalyst chemical reaction catalyst: Some chromium compounds are used as catalysts in organic synthesis and other chemical reactions to promote the reaction and increase the reaction rate, such as the application of chromate in organic synthesis. 2. Water treatment chromium salt precipitation: Some chromium compounds are used in water treatment processes to help improve water quality by precipitating and removing heavy metal pollutants. 3. Analytical chemistry analytical reagent: Some chromium compounds (such as potassium chromate) are used in analytical chemistry for redox reactions and quantitative analysis, and are an important analytical reagent.