MERCUROUS CHLORIDE Property

Melting point:

400 °C (subl.)(lit.)

Boiling point:

383°C

Density 

7.15

vapor pressure 

1.7 mm Hg at 236 °C

storage temp. 

Poison room

solubility 

insoluble in ethanol, ethyl ether

form 

powder

Specific Gravity

7.15

color 

White

Odor

Odorless

Water Solubility 

Soluble in (0.002g/L )water.

Sensitive 

Moisture & Light Sensitive

Merck 

14,5894

Solubility Product Constant (Ksp)

pKsp: 17.88（25°C）

Exposure limits

ACGIH: TWA 0.025 mg/m3 (Skin)
NIOSH: IDLH 10 mg/m3; TWA 0.05 mg/m3; Ceiling 0.1 mg/m3

Dielectric constant

7.0（Ambient）

InChIKey

ZOMNIUBKTOKEHS-UHFFFAOYSA-L

CAS DataBase Reference

10112-91-1(CAS DataBase Reference)

NIST Chemistry Reference

Mercurous chloride(10112-91-1)

EPA Substance Registry System

Mercurous chloride (10112-91-1)

Safety

Hazard Codes 

Xn,N

Risk Statements 

22-36/37/38-50/53

Safety Statements 

13-24/25-46-60-61

RIDADR 

UN 2811 6.1/PG 3

WGK Germany 

3

RTECS 

OV8740000

TSCA 

Yes

HazardClass 

6.1

PackingGroup 

II

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H334May cause allergy or asthma symptoms or breathing difficulties if inhaled

H335May cause respiratory irritation

H400Very toxic to aquatic life

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P284Wear respiratory protection.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P342+P311IF experiencing respiratory symptoms: call a POISON CENTER or doctor/physician.

P405Store locked up.

MERCUROUS CHLORIDE Chemical Properties,Usage,Production

Chemical Properties

Mercury (I) chloride is a dense white powder and insoluble in water and may be light sensitive. It is incompatible with strong bases, carbonates, sulphides, cyanides, alkalis, sulphites, sulphates, hydrogen peroxide, ammonia, iodine, and hydrogen bromide.

Uses

Mercury(I) chloride is used in calomel electrodes; in ceramic painting; as a fungicide; in pyrotechnics for producing dark green light; in agriculture for controlling root maggots; and as an antiseptic and antisyphilitic agent in medicine.

Preparation

Mercury(I) chloride is prepared by passing a limited amount of chlorine gas over mercury in a heated silica retort. Excess chlorine should be avoided as it can oxidize mercury(I) chloride to mercury(II) chloride.
2Hg + Cl2 → Hg2Cl2
The product generally contains some mercury(II) chloride which is removed by treating the product mixture with water and filtering out the insoluble mercury(I) salt from the soluble mercury(II) salt.
The compound also can be made by heating mercury(II) chloride with mercury. The product Hg2Cl2 sublimes and is collected:
HgCl2 + Hg → Hg2Cl2
Mercury(I) chloride is obtained as a white precipitate by adding a cold acidic solution of sodium chloride or other soluble chloride to a solution of mercurous salt, such as mercury(I) nitrate:
[Hg2]²⁺ (aq) + 2Cl¯ (aq) → Hg2Cl2 (s)
The precipitation method, however, does not form high-purity product as it contains small amounts of reactant and product ions that stick to the Hg2Cl2 precipitate and are difficult to remove by washing with water.

Reactions

Mercury(I) chloride oxidizes to mercury(II) chloride when heated with chlorine:
Hg2Cl2 + Cl2 → 2HgCl2
Mercury(I) chloride is a reducing agent and, therefore, its reaction with oxidizing substances can oxidize it to Hg(II) compounds.
When heated at elevated temperatures, it partially dissociates to mercury metal and mercury(II) chloride:
Hg2Cl2 → Hg + HgCl2
This disproportionation (or breakdown of a compound into two products containing the same element but in different oxidation states) also occurs to some degree when mercury(I) chloride is heated and sublimed in an open container. Reaction with ammonia in solution forms an unstable black adduct which slowly converts to mercury(II) amidochloride, NH2HgCl, releasing mercury:
Hg2Cl2 + 2NH3 → ClHg—HgNH2 + NH4Cl
ClHg—HgNH2 → NH2HgCl + Hg

Toxicity

Mercury(I) chloride is highly toxic by ingestion and other routes of exposure. The symptoms include nausea, vomiting, abdominal pain, diarrhea and kidney damage.

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

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).

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.

Uses

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

Uses

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.

Uses

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

Definition

ChEBI: Dimercury dichloride is a mercury coordination entity.

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.

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.