5879. Mercuric Iodide, Red

Nomenclature

CAS number: 7774-29-0
Mercury iodide (HgI2); mercury biniodide; diiodomercury.
HgI2; mol wt 454.40.
Hg 44.14%, I 55.86%.

Properties

Scarlet-red, heavy, odorless, almost tasteless powder; sensitive to light; at 130° becomes yellow, and then red on cooling. Poisonous. d 6.28. mp 259°. bp ≈350° and sublimes. Soly in water (25°) 0.006 g/100 g. 1 g dissolves in 115 ml alcohol, 20 ml boiling alcohol, about 120 ml ether, about 60 ml acetone, 910 ml chloroform, 75 ml ethyl acetate, 260 ml carbon disulfide, readily in alkali iodides, HgCl2, Na2S2O3; sol in 230 ml olive oil, 50 ml castor oil. Protect from light.

Use

In analytical chemistry for preparation of Nessler's Reagent (alkaline mercuric potassium iodide solution).

Therapeutic Category

Antiseptic (topical).

Therapeutic Category (Veterinary)

Has been used as a topical antiseptic, counterirritant, vesicant.