Mercury(II) sulfide Property

Melting point:

583.5 °C(lit.)

Boiling point:

584°C

Density 

8.1 g/mL at 25 °C

solubility 

insoluble in H2O; soluble in acid solutions, ethanol

form 

Powder

color 

red

Water Solubility 

Soluble in water (0.00001 g/L).

Crystal Structure

Cubic, Sphalerite Structure - Space Group F(-4)3m

Merck 

14,5888

Solubility Product Constant (Ksp)

pKsp: 52.4

Exposure limits

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

Stability:

Stable.

CAS DataBase Reference

1344-48-5(CAS DataBase Reference)

EPA Substance Registry System

Mercury sulfide (HgS) (1344-48-5)

Safety

Hazard Codes 

N-T,Xi

Risk Statements 

50/53-36-33-23/24/25-43-31

Safety Statements 

61-60-45-36/37/39-28A-26-36/37

RIDADR 

2025

WGK Germany 

-

RTECS 

OX0720000

F 

8

TSCA 

Yes

HazardClass 

6.1

PackingGroup 

II

HS Code 

28521000

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H317May cause an allergic skin reaction

Precautionary statements

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

P272Contaminated work clothing should not be allowed out of the workplace.

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

P302+P352IF ON SKIN: wash with plenty of soap and water.

P333+P313IF SKIN irritation or rash occurs: Get medical advice/attention.

Mercury(II) sulfide Chemical Properties,Usage,Production

Physical Properties

Mercury(II) sulfide has several modifications, the only two stable allotropic forms are:
1. the red hexagonal form known as cinnabar (alpha form), and 2. the black cubic modification (beta form).
Cinnabar is a red crystalline or powdery substance; hexagonal crystal system; refractive index 2.854; density 8.10 g/cm3; sublimes at 583.5°C; color changes to brown at 250°C and converts to black sulfide at 386°C; reverts to red color on cooling; insoluble in water, alcohol and nitric acid; soluble in aqua regia and solutions of alkali metal sulfides; decomposed by hot concentrated sulfuric acid.
Black sulfide is a black amorphous powder or crystalline substance (beta form); cubic structure; metastable at ordinary temperatures; converts to red sulfide by sublimation at ordinary pressure; density 7.73 g/cm3; melts at 583.5°C; insoluble in water, alcohol and nitric acid; soluble in aqua regia, alkalies, and solutions of alkali metal sulfides.

Preparation

Red sulfide occurs natively and is mined from mineral cinnabar. Also it can be prepared by heating mercury with a solution of potassium pentasulfide, producing a scarlet cinnabar:
Hg + K2S5 → HgS + K2S4
The red sulfide also may be made from black sulfide by heating in a concentrated solution of alkaline polysulfide. The shade of pigment varies with temperature, reaction time, and concentration of the black sulfide.
Alternatively, vermilion may be made by grinding sodium sulfide with sulfur and slowly adding mercury. The shades are not bright when prepared at 0°C.
The black mercury(II) sulfide is prepared usually by precipitation from an aqueous solution of mercury(II) salt with hydrogen sulfide. Thus, when H2S is passed into a solution of HgCl2, a pale yellow precipitate of composition HgCl2•2HgS forms. This converts to amorphous black HgS on further treatment with H2S.
The black sulfide may also be made by other methods such as adding sodium thiosulfate, Na2S2O3 in excess to a dilute solution of sodium mercurichloride, Na2HgCl4 and treating mercury with molten or powdered sulfur.

Reactions

When heated in a current of air, mercury(II) sulfide is converted into metallic mercury and sulfur dioxide:
HgS + O2 → Hg + SO2
Similar reduction to metallic mercury occurs when the sulfide is heated with several metals or metal oxides:
HgS + Fe → Hg + FeS
4HgS + 4CaO → 4Hg + 3CaS + CaSO4
Mercury(II) sulfide dissolves in concentrated solutions of alkali or alkalineearth metal sulfides forming thiosalts, such as Na2[HgS2]•xH2O. Such thiosalts are stable in solution only when alkaline hydroxides are present in excess. These salts also are obtained as bright and deliquescent needles when HgS is heated with sulfur and alkaline hydroxides.

Chemical Properties

Fine, bright-scarlet powder.Insoluble in water and alcohol.

Uses

Mercuric sulfide (HgS) is a fine, very brilliant scarlet powder that is deadly if ingested. Also known as the mercury ore cinnabar and metacinnabar, it is used as a pigment in the manufacture of paints.

Uses

Mercury(II) sulfide is used in paint, sealing wax and preservatives.

Uses

For coloring plastics, sealing wax, and with FeSO4 for marking linen; manufacture of fancy colored papers; as pigment.

Definition

cinnabar: A bright red mineralform of mercury(II) sulphide, HgS,crystallizing in the hexagonal system;the principal ore of mercury. Itis deposited in veins and impregnationsnear recent volcanic rocks andhot springs. The chief sources includeSpain, Italy, and Yugoslavia.

Air & Water Reactions

Readily oxidized as to be pyrophoric in air [Bretherick 1979. p. 120].

Reactivity Profile

Inorganic reducing agents, such as MERCURY(II) SULFIDE, react with oxidizing agents to generate heat and products that may be flammable, combustible, or otherwise reactive.

Hazard

Highly toxic by ingestion, inhalation, and skin absorption.

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. If ingested, toxicity depends on release of t he Hg ++ ion; chronic mercury poisoning can cause kidney, mental, and nervous disturbances. Dust irritates eyes and frequently causes allergic dermatitis; absorption through skin can cause systemic poisoning.