Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the Chlor-alkali process.
Sulfites or sulphites are compounds that contain the sulfite ion, SO2−
3. The sulfite ion is the conjugate base of bisulfite. Although its acid is elusive, its salts are widely used.
Sodium sulfite (sodium sulphite) is the inorganic compound with the chemical formula Na2SO3. A white, water-soluble solid, it is used commercially as an antioxidant and preservative. It is also suitable for the softening of lignin in the pulping and refining processes of wood and lignocellulosic materials. A heptahydrate is also known but it is less useful because of its greater susceptibility toward oxidation by air.
Sodium thiosulfate is an inorganic compound with the formula Na2S2O3·(H2O)(x) .Typically it is available as the white or colorless pentahydrate, It is a white solid that dissolves well in water. The compound is a reducing agent and a ligand, and these properties underpin its applications.
In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. The reverse of disproportionation, such as when a compound in an intermediate oxidation state is formed from precursors of lower and higher oxidation states, is called comproportionation, also known as synproportionation.
Sodium chlorite (NaClO2) is a chemical compound used in the manufacturing of paper and as a disinfectant.
A relaxer is a type of lotion or cream generally used by people with tight curls or very curly hair which makes hair easier to straighten by chemically "relaxing" the natural curls. The active agent is usually a strong alkali, although some formulations are based on ammonium thioglycolate or formaldehyde.
Sodium dithionite is a white crystalline powder with a sulfurous odor. Although it is stable in dry air, it decomposes in hot water and in acid solutions.
Potassium metabisulfite, K2S2O5, also known as potassium pyrosulfite, is a white crystalline powder with a pungent odour. It is mainly used as an antioxidant or chemical sterilant. As a disulfite, it is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably. Potassium metabisulfite has a monoclinic crystal structure.
The dithionite is the oxyanion with the formula [S2O4]2−. It is commonly encountered as the salt sodium dithionite. For historical reasons, it is sometimes called hydrosulfite, but it contains no hydrogen and is not a sulfite. The dianion has a steric number of 4 and trigonal pyramidal geometry.
Thiosulfate is an oxyanion of sulfur with the chemical formula S2O2−3. Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid, e.g. sodium thiosulfate Na2S2O3. Thiosulfate also refers to the esters of thiosulfuric acid. The prefix thio- indicates that the thiosulfate is a sulfate with one oxygen replaced by sulfur. Thiosulfate is tetrahedral at the central S atom. Thiosulfate salts occur naturally. Thiosulfate ion has C3v symmetry, and is produced by certain biochemical processes. It rapidly dechlorinates water and is notable for its use to halt bleaching in the paper-making industry. Thiosulfate salts are mainly used in dying in textiles and the bleaching of natural substances.
Caramel color or caramel coloring is a water-soluble food coloring. It is made by heat treatment of carbohydrates (sugars), in general in the presence of acids, alkalis, or salts, in a process called caramelization. It is more fully oxidized than caramel candy, and has an odor of burnt sugar and a somewhat bitter taste. Its color ranges from pale yellow to amber to dark brown.
Potassium bisulfite (or potassium hydrogen sulfite) is a chemical mixture with the approximate chemical formula KHSO3. Potassium bisulfite in fact is not a real compound, but a mixture of salts that dissolve in water to give solutions composed of potassium ions and bisulfite ions. It is a white solid with an odor of sulfur dioxide. Attempts to crystallize potassium bisulfite yield potassium metabisulfite, K2S2O5.
The sulfite process produces wood pulp that is almost pure cellulose fibers by treating wood chips with solutions of sulfite and bisulfite ions. These chemicals cleave the bonds between the cellulose and lignin components of the lignocellulose. A variety of sulfite/bisulfite salts are used, including sodium (Na+), calcium (Ca2+), potassium (K+), magnesium (Mg2+), and ammonium (NH4+). The lignin is converted to lignosulfonates, which are soluble and can be separated from the cellulose fibers. For the production of cellulose, the sulfite process competes with the Kraft process which produces stronger fibers and is less environmentally costly.
The Wellman–Lord process is a regenerable process to remove sulfur dioxide from flue gas without creating a throwaway sludge product.
Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical mixture with the approximate chemical formula NaHSO3. Sodium bisulfite in fact is not a real compound, but a mixture of salts that dissolve in water to give solutions composed of sodium and bisulfite ions. It appears in form of white or yellowish-white crystals with an odor of sulfur dioxide. Regardless of its ill-defined nature, sodium bisulfite is used in many different industries such as a food additive with E number E222 in the food industry, a reducing agent in the cosmetic industry, and a decomposer of residual hypochlorite used in the bleaching industry.
Ammonium thiosulfate is an inorganic compound with the formula [NH4]2S2O3. It is white crystalline solid with ammonia odor, readily soluble in water, slightly soluble in acetone and insoluble in ethanol and diethyl ether.
The topic of sulfite food and beverage additives covers the application of sulfites in food chemistry. "Sulfite" is jargon that encompasses a variety of materials that are commonly used as preservatives or food additive in the production of diverse foods and beverages. Although sulfite salts are relatively nontoxic, their use has led to controversy, resulting in extensive regulations. Sulfites are a source of sulfur dioxide (SO2), a bactericide.
Potassium thiosulfate, commonly abbreviated KTS, is an inorganic compound with the formula K2S2O3. This salt can form multiple hydrates, such as the monohydrate, dihydrate, and the pentahydrate, all of which are white or colorless solids. It is used as a fertilizer.
