Product Name: Hydrogen Sulfide

CAS: 7783-06-4

Molecular Formula: H2S

Molecular Weight: 34.08

EINECS: 231-977-3

Hydrogen sulfide

Hydrogen sulfide is a hydride of sulfur with the chemical formula H2S. It is a colorless, foul-smelling (rotten egg) highly toxic gas. It is soluble in water and ethanol, with a specific gravity of 1.1906. Melting point -85.5°C, boiling point -60.4°C, critical temperature 100.4°C, critical pressure 90.06×105 Pa. The autoignition point is 260°C, it is flammable, it can cause explosive combustion when encountering sparks, and it can cause explosion when mixed with air, with an explosion limit of 4% to 44% (volume). It can react chemically with a variety of ions to produce water-insoluble sulfides, which can turn the surface of copper and silver black. It is widely present in the manufacturing industries of metal smelting, natural gas, hydrochloric acid and sulfuric acid. Hydrogen sulfide gas is often discharged when manufacturing various sulfides such as sulfate pulp, rayon, artificial cotton, rubber, carbon disulfide, etc. In some chemical reactions, unstable sulfur compounds will also decompose to produce hydrogen sulfide, such as in coking, refined petroleum and metal smelting. As a common waste gas, hydrogen sulfide is very easy to leak into the air. The decomposition of sulfur dyes can also release hydrogen sulfide gas.

Hydrogen sulfide Properties

Chemical properties

Hydrogen sulfide is a colorless acidic gas with a foul smell like rotten eggs. Relative density 1.5392 (0℃). Melting point 85.5℃. Boiling point -60.3℃. Critical temperature 100.5℃. Critical pressure 9.0×103Pa. Heat of vaporization 18.67kJ/mol; heat of fusion 23.80kJ/mol. Vapor pressure 2.7kPa (25.5℃). Vapor relative density 1.19. Ignition point 260℃. Explosion limits: lower limit is 4.3% (volume), upper limit is 40.0% (volume). The permissible concentration in air is 10×10-6 (ppm). Soluble in water, ethanol, glycerol, and carbon disulfide. Very soluble in organic amines. Also has a large solubility in caustic soda solutions. Combustion in excess oxygen generates sulfur dioxide and water, and when oxygen supply is insufficient, generates water and free sulfur. Stable at room temperature.

Uses

1. Hydrogen sulfide is used to synthesize fluorescent powder, electroluminescence, photoconductors, photoelectric exposure meters, etc. Reducing agent for organic synthesis. Used in metal refining, pesticides, medicines, and catalyst regeneration. General reagent. Preparation of various sulfides

2. Used to separate and identify metal ions, purify hydrochloric acid and sulfuric acid, and prepare elemental sulfur

3. Can be used to convert sulfur and sulfuric acid to produce sodium sulfide and sodium hydrosulfide, or to produce organic sulfur compounds such as thiophene, mercaptan and thioether, etc.

Production method

20% to 30% phosphoric acid is slowly dripped from a separatory funnel into a concentrated aqueous solution of Na2S?9RO. The generated gas is dried with anhydrous calcium chloride and phosphorus pentoxide to obtain hydrogen sulfide gas, which is liquefied and pressed into a cylinder. Hydrogen sulfide produced by direct synthesis of sulfur and hydrogen has high purity.