I.Physical Properties
Sulphur is a light yellow or yellow solid, usually in crystalline or amorphous form. It has a density of 2.07 grams per cubic centimetre, a melting point between 112.8°C and 119.3°C, and a boiling point of 444.6°C. Sulphur is insoluble in water but slightly soluble in alcohol and ethers, and is soluble in carbon disulphide, carbon tetrachloride and benzene. At room temperature, sulphur is relatively chemically stable, but its properties change when heated.
II. Chemical Properties
Sulphur is chemically very reactive and can combine with oxygen, hydrogen, halogens (except iodine) and most metal elements. It has both oxidising and reducing properties. For example, when sulphur reacts with oxygen, it forms sulphur dioxide, showing its reducing nature; when it reacts with metals to form sulphides, it shows its oxidising nature. When sulphur burns in air, it emits a blue flame and produces sulphur dioxide. In addition, sulphur can react with strong alkali solutions to form sulphides and sulphites.
III. Application Fields
Sulphur has a wide range of applications in industry and agriculture. In the chemical industry, sulphur is mainly used to produce sulphuric acid, which is a key raw material for manufacturing phosphates such as diammonium phosphate and monoammonium phosphate. In the rubber industry, sulphur is used in the vulcanisation of rubber to enhance its wear and corrosion resistance. In agriculture, sulphur can be used as a fungicide, insecticide and herbicide, such as in lime sulphur. In addition, sulphur is used in the pharmaceutical industry for its antibacterial properties and is commonly found in pharmaceuticals and skincare products like sulphur soap and drugs for skin diseases. Other application areas include fireworks, dyes, pesticides and metal smelting.
IV. Usage Norms and Safety Precautions
Sulphur is a flammable solid with an autoignition temperature of 205°C, so it should be stored and transported away from sources of ignition and heat. Sulphur dust can form explosive mixtures when mixed with air, so dust dispersion should be avoided during handling. Although sulphur itself is low in toxicity, the sulphur dioxide and hydrogen sulphide gases produced during combustion are harmful to humans, so operations should be carried out in well-ventilated environments. Sulphur should be stored in a dry, well-ventilated warehouse, away from oxidisers and acids.
