Sodium carbonate is also used as a relatively strong base in various settings. Soda lime glass has been the most common form of glass for centuries. This type of glass is known as soda lime glass: "soda" for the sodium carbonate and "lime" for the calcium carbonate. This "soda glass" is mildly water-soluble, so some calcium carbonate is added to the melt mixture to make the glass produced insoluble. Sodium carbonate acts as a flux for silica, lowering the melting point of the mixture to something achievable without special materials. The manufacture of glass is one of the most important uses of sodium carbonate. It is synthetically produced in large quantities from salt -sodium chloride- and limestone by a method known as the Solvay process. Because the ashes of these sodium-rich plants were noticeably different from ashes of timber -used to create potash-, they became known as "soda ash". Historically it was extracted from the ashes of plants growing in sodium-rich soils, such as vegetation from the Middle East, kelp from Scotland and seaweed from Spain. Sodium carbonate is well known domestically for its everyday use as a water softener. It has a strongly alkaline taste, and forms a moderately basic solution in water. Pure sodium carbonate is a white, odorless powder that is hygroscopic -absorbs moisture from the air.
It most commonly occurs as a crystalline decahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate: Sodium carbonate, Na2CO3, -also known as washing soda, soda ash and soda crystals, and in the monohydrate form as crystal carbonate- is the water-soluble sodium salt of carbonic acid. In cooking, it is sometimes used as an emulsifier and to prevent sticking, for example in nonstick cooking spray. Lecithin is sold as a food additive and dietary supplement. This results in a type of surfactant that usually is classified as amphipathic. In aqueous solution, its phospholipids can form either liposomes, bilayer sheets, micelles, or lamellar structures, depending on hydration and temperature. It has low solubility in water, but is an excellent emulsifier. It is usually available from sources such as soybeans, eggs, milk, marine sources, rapeseed, cottonseed, and sunflower.
Lecithin can easily be extracted chemically using solvents such as hexane, ethanol, acetone, petroleum ether, benzene, etc., or extraction can be done mechanically. Gobley originally isolated lecithin from egg yolk-λέκιθος lekithos is "egg yolk" in Ancient Greek-and established the complete chemical formula of phosphatidylcholine in 1874 in between, he had demonstrated the presence of lecithin in a variety of biological matters, including venous blood, in human lungs, bile, human brain tissue, fish eggs, fish roe, and chicken and sheep brain. In 1850, he named the phosphatidylcholine lécithine. Lecithin: Lecithin -UK:, US:, from the Greek lekithos, "egg yolk"- is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, which are amphiphilic – they attract both water and fatty substances -and so are both hydrophilic and lipophilic-, and are used for smoothing food textures, dissolving powders -emulsifying-, homogenizing liquid mixtures, and repelling sticking materials.Lecithins are mixtures of glycerophospholipids including phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and phosphatidic acid.Lecithin was first isolated in 1845 by the French chemist and pharmacist Theodore Gobley.
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