MERCUROUS CHLORIDE

Description

Mercury(I) chloride, a colorless solid also known as the mineral calomel, is the compound with the formula Hg2Cl2, with the connectivity Cl-Hg-Hg-Cl. It reacts with chlorine to form mercuric chloride, which resists further oxidation. Hg2Cl2 is a linear molecule. Mercurous chloride forms through the reaction of elemental mercury and mercuric chloride.
Hg + HgCl2→Hg2Cl2

Chemical properties

White, rhombic crystals or crystalline powder; odorless. Stable in air but darkens on exposure to light.decomposed by alkalies. Insoluble in water, ether, alcohol, and cold dilute acids.

Chemical properties

Mercurous chloride forms tetrahedral white crystals, and, unlike the mercuric salt, is only very slightly soluble in water (about 2mg/L water at 20°C).

The Uses of MERCUROUS CHLORIDE

Dark green Bengal lights; calomel paper, mixed with gold in painting on porcelain; for calomel electrodes; as fungicide; in agriculture to control root maggots on cabbage and onions.

The Uses of MERCUROUS CHLORIDE

This compound is used by the pharmaceutical industry and is used also as a fungicide, as a poison, in fireworks, and to control maggots.

The Uses of MERCUROUS CHLORIDE

Calomel is used as a laboratory reagent, as a fungicide, and as a depolarizer in dry batteries.

Production Methods

Mercurous chloride is produced by exposing mercury metal to limited amounts of chlorine gas, insufficient to form mercuric chloride as the major product; it can also be prepared by precipitation from mercurous nitrate solution.

Definition

ChEBI: Dimercury dichloride is a mercury coordination entity.

General Description

Odorless white solid. Sinks in water.

Reactivity Profile

MERCUROUS CHLORIDE is incompatible with acetylene, ammonia, chlorine dioxide, azides, calcium (amalgam formation), sodium carbide, lithium, rubidium, copper .

Hazard

Toxic dose is uncertain.

Health Hazard

Acute poisoning can result from inhaling dust concentrations of 1.2-8.5 mg/m 3 in air; symptoms include pain and tightness in chest, coughing, and difficulty in breathing. Compound is an irritant, cathartic, or purgat ive; rarely, ``calomel sickness,'' a benign reaction with fever and rash, appears after about 1 week; seldom causes systemic poisoning but may be fatal if retained to 30-40 mg/kg. Contact with eyes causes mild irritation.

Carcinogenicity

An acute oral dose in humans of 1 g HgCl₂ may cause corrosive damage to the GI tract; there is, however, little quantitative information on dose–effect relationships during low-level exposure to inorganic mercury. A dose of 2 g may be expected to increase mortality greatly among victims of the poison. Death from acute oral exposure is usually caused by cardiovascular collapse and renal failure. Ingestion of inorganic compounds may cause gastrointestinal corrosion and irritation, such as vomiting, bloody diarrhea, and stomach pains.

Environmental Fate

Calomel can generate reactive oxygen species and deplete glutathione levels. Both genotoxic and nongenotoxic mechanisms may contribute to renal carcinogenic effect of mercury.

Toxicity evaluation

Calomel decomposes gradually in the presence of sunlight. It slowly decomposes to mercury and mercuric chloride under aqueous conditions.