Molecular Formula | H2S |
Molar Mass | 34.08 |
Density | dgas 1.19 (air = 1.00) |
Melting Point | −85°C(lit.) |
Boling Point | −60°C(lit.) |
Flash Point | -17℃ |
Water Solubility | 1g dissolves in H2O: 187mL (10°C), 242mL (20°C), 314 (30°C) [MER06] |
Vapor Presure | 252 psi ( 21 °C) |
Vapor Density | 1.19 (15 °C, vs air) |
Appearance | colorless gas |
Odor | Strong rotten egg odor detectable at 0.001 to 0.1 ppm (mean = 0.0094 ppm);olfactory fatigue occurs q |
Merck | 13,4823 |
BRN | 3535004 |
pKa | 7(at 25℃) |
Storage Condition | 2-8°C |
Stability | Stable. Highly flammable. May form explosive mixture with air. Note wide explosive limits. Incompatible with strong oxidizing agents, many metals. May react violently with metal oxides, copper, fluori |
Explosive Limit | 6% |
Physical and Chemical Properties | A colorless, egg-like stench of acid gases. Relative density 1.5392(0 degrees C). Melting point 85.5 °c. Boiling point -60.3 °c. The critical temperature is 100.5. The critical pressure is 9.0 × 103Pa. Heat of vaporization: 18.67 kJ/mol; Heat of fusion: 23.80 kJ/mol. Vapor pressure 2.7 kPa(25.5 C). The relative density of the vapor was 1.19. Ignition point: 260 ℃. Explosive limit: the lower limit is 4.3% by volume and the upper limit is 40.0% by volume. The allowable concentration in air is 10 x 10-6(ppm). Soluble in water, ethanol, glycerol, carbon disulfide. The solubility in organic amines is extremely high. There is also greater solubility in caustic solutions. Sulfur dioxide and water are generated by combustion in excess oxygen, and water and free sulfur are generated when the oxygen supply is insufficient. Stable at room temperature. |
Use | Can be used for the conversion of sulfur and sulfuric acid, the production of sodium sulfide and sodium hydrosulfide, or for the production of organic sulfur compounds such as thiophene, mercaptans and sulfide |
Risk Codes | R12 - Extremely Flammable R26 - Very Toxic by inhalation R50 - Very Toxic to aquatic organisms R40 - Limited evidence of a carcinogenic effect R36/37 - Irritating to eyes and respiratory system. R19 - May form explosive peroxides R11 - Highly Flammable |
Safety Description | S9 - Keep container in a well-ventilated place. S16 - Keep away from sources of ignition. S36 - Wear suitable protective clothing. S38 - In case of insufficient ventilation, wear suitable respiratory equipment. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S28 - After contact with skin, wash immediately with plenty of soap-suds. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
UN IDs | UN 1053 2.3 |
WGK Germany | 2 |
RTECS | MX1225000 |
Hazard Class | 2.3 |
Toxicity | LC50 in mice, rats (ppm): 634, 712 (1 hr inhalation) (Vernot); LC50 in rats (ppm): 444 (4 hr inhalation) (Tansy) |
Raw Materials | Sulfur(α) Hydrogen |
Downstream Products | Sodium sulfide sodium hydrosulfide Strontium carbonate,nanometre Tetrahydrothiophene Thiourea |
a colorless, flammable, toxic gas or liquid, with a special smell of bad eggs. Melting Point -85. 49 °c; Boiling point -60. 33. Relative density (gas) 1.19 (Air 1. 00); Vapor pressure 18. 75 x Pa 10s. Soluble in water, alcohol, ether and other organic solvents. 1g of H2S was dissolved in water 187mL(10 °c) water, 242mL (20 °c), 314mL (30 °c).
The pure hydrogen is depressurized and then sent to the dryer for further purification, and then metered into the bottom of the reactor for direct contact reaction with sulfur to generate hydrogen sulfide, which is washed by the scrubber, the remaining sulfur vapor is condensed by re-entering the sulfur vapor condenser. Pure hydrogen sulfide gas is compressed by the press and enters the hydrogen sulfide condenser, and the liquid hydrogen sulfide is collected in the storage tank.
It is used in the manufacture of large scale integrated circuits and the production of phosphor for picture tubes in the electronic industry.
mice, rats inhaled LCso:634 x 10-6/1H, 712 x 10-6 /lh; Rats inhaled LCso:444 x 10-6 /4H. Hydrogen sulfide is mainly absorbed by the respiratory tract, human inhalation (70~150mg/m3 )1(1~2H), respiratory tract and eye irritation symptoms, hydrogen sulfide can paralyze the olfactory nerve, after 2~5min, no longer smell the odor. Inhalation (300mg/m3 )/1h,6~8min, eye acute irritation symptoms, slightly prolonged exposure to cause pulmonary edema. Inhalation of hydrogen sulfide can cause depression of the central nervous system, sometimes leading to eventual death due to irritation and paralysis of breathing. High concentrations of hydrogen sulfide in a few seconds will occur collapse, Shock, can lead to respiratory tract inflammation, pulmonary edema, and accompanied by Head Pain, chest pain and Dyspnea. No oxygenated combustible materials, acids or other corrosive materials should be present near the hydrogen sulfide storage area. Avoid exposure to high temperatures.
FEMA | 3779 | HYDROGEN SULFIDE |
olfactory Threshold | 0.00041ppm |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
hydrogen sulfide | hydrogen sulfide is a hydride of sulfur with the chemical formula H2S. A colorless, highly toxic gas with a bad odor (the smell of a bad egg). Soluble in water and ethanol, the specific gravity of 1.1906. Melting Point -85.5°C, boiling point -60.4°C, critical temperature 100.4°C, critical pressure 90.06 x 105 Pa. The spontaneous ignition point is 260 ° C. It is flammable, and it can cause explosion combustion when it is mixed with air. When it is mixed with air, it can cause explosion, and the explosion limit is 4%~ 44% (volume). With a variety of chemical ion, the formation of water-insoluble sulfide, can make copper, silver surface blackening. It is widely used in the manufacturing industry of metal smelting, natural gas, hydrochloric acid and sulfuric acid. In the manufacture of kraft pulp, rayon, rayon, rubber, carbon disulfide and other sulfides, hydrogen sulfide gas is often discharged. In some chemical reactions, the instability of sulfur compounds will also decompose hydrogen sulfide, such as: Coking, refined oil and metal smelting, hydrogen sulfide as a conventional waste gas, easy to leak into the air. Decomposition of sulfur dyes can also evolve hydrogen sulfide gas. Hydrogen sulfide ionized in water, is a binary weak acid, known as hydrogen sulfuric acid: Figure 1: hydrogen sulfide ionized in water to produce hydrogen sulfuric acid in air, hydrogen sulfuric acid can be gradually oxidized by oxygen, the precipitation of sulfur and turbidity must be prepared temporarily before use. Hydrogen sulfide is chemically unstable and decomposes to hydrogen and sulfur when heated. Combustion in the air produces water and sulfur dioxide. Elemental sulfur can be obtained by combustion in insufficient air. Sulfur in hydrogen sulfide is easy to give electrons, so it is a good reducing agent. For example, in acidic medium, it can reduce Fe3 + to Fe2 +, reduce Br2 to Br-, reduce MnO-4 to Mn2 +, and reduce Cr2O2-7 to Cr3 +, HNO3 is reduced to NO2, etc., and hydrogen sulfide is oxidized to elemental sulfur or sulfite or sulfate. Hydrogen sulfide and SO2 react in humid air to form elemental sulfur (the reverse reaction of the disproportionation reaction). Hydrogen sulfide can make the surface of silver, copper and other products black, and many metal ions, the formation of sulfide precipitation insoluble in water or acid. In the laboratory is often used for the separation and identification of metal ions. Hydrogen sulfide in the laboratory commonly used FeS and dilute hydrochloric acid to produce. Hydrogen reacts with sulfur only when heated to form hydrogen sulfide. |
solubility in water (g/100ml) | grams dissolved per 100ml of water: 0.33g/20 ℃ |
toxic | toxic! Mainly by respiratory absorption caused by systemic poisoning, is a chemical asphyxiating gas. Acute poisoning occurs when the exposure concentration exceeds 700 x 10-6. If not timely treatment, will die. Low concentrations of gas can stimulate respiratory organs and eyes, and Head Pain, dizziness, weakness and other symptoms. Cough, conjunctivitis. All-body protective clothing including oxygen gas masks must be worn during operation. For the inhalation of vapor, the patient is separated from the contaminated area, placed in a place with fresh air and kept warm. Severe cases should be diagnosed and treated. If breathing stops, artificial respiration should be performed immediately. Eye irritation must be flushed with plenty of water and treated with a doctor. |
Application | is used in the manufacture of synthetic phosphors, electroluminescent, photoconductor, photoelectric exposure meter, etc. Organic synthetic reducing agents. Used for metal refining, pesticide, medicine, Catalyst regeneration. General reagents. Preparation of various sulfides. it can be used for separation and identification of metal ions, purification of hydrochloric acid and sulfuric acid, and preparation of elemental sulfur it can be used for conversion of sulfur and sulfuric acid, production of sodium sulfide and sodium hydrosulfide, or for the production of organic sulfur compounds such as thiophene, mercaptans and sulfide, etc. |
production method | slowly drop 20% ~ 30% phosphoric acid from a separatory funnel to Na2S? In the concentrated aqueous solution of 9RO, the generated gas is dried by anhydrous calcium chloride and phosphorus pentoxide to obtain hydrogen sulfide gas, which is liquefied and pressed into a steel cylinder. Hydrogen sulfide with high purity was obtained by direct synthesis of sulfur and hydrogen. |
category | hazardous gas |
toxicity grade | poisoning |
Acute toxicity | inhalation-rat LC50:666 mg/m3; Inhalation-mouse LC50:951 mg/m3/1 h |
explosive hazard characteristics | mixture explosive with Air |
flammability hazard characteristics | flammability; Toxic NOx smoke from combustion |
storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; It is stored separately from nitric acid and strong oxidant |
fire extinguishing agent | water, sand, foam |
Occupational Standard | TWA 15 mg/m3; Tel 23 mg/m3 |
spontaneous combustion temperature | 260°C |
DOT Classification | 2.3, Hazard Zone B (Gas poisonous by inhalation) |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
immediate life-and health-threatening concentration | 100 ppm |