Mercury(II) chloride is used as a catalyst in making plastics, depolarizer in batteries and as a reagent in organic synthesis and analytical chemistry. It is also used to prepare an amalgam with metals such as aluminum, which finds application as reducing agent in organic synthesis. It also finds application in photography as a photographic intensifier. Further, it serves as a preservative and used in the treatment of syphilis. It is also used to remove dithiane groups bonded to a carbonyl in an umpolung reaction.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.