Mercury(II) nitrate is an inorganic compound with the chemical formula . It is the mercury(II) salt of nitric acid . It contains mercury(II) cations and nitrate anions, and water of crystallization in the case of a hydrous salt. Mercury(II) nitrate forms hydrates . Anhydrous and hydrous salts are colorless or white soluble crystalline solids that are occasionally used as a reagents. Mercury(II) nitrate is made by treating mercury with hot concentrated nitric acid. Neither anhydrous nor monohydrate has been confirmed by X-ray crystallography.[1] The anhydrous material is more widely used.
Mercury(II) nitrate is used as an oxidizing agent in organic synthesis, as a nitrification agent, as an analytical reagent in laboratories, in the manufacture of felt, and in the manufacture of mercury fulminate.[2] An alternative qualitative Zeisel test can be done with the use of mercury(II) nitrate instead of silver nitrate, leading to the formation of scarlet red mercury(II) iodide.[3]
Mercury compounds are highly toxic. The use of this compound by hatters and the subsequent mercury poisoning of said hatters is a common theory of where the phrase "mad as a hatter" came from.