Sodium Carbonate is used in cooking for a variety of reasons,including the fact that it is a stronger base than baking soda (sodiumbicarbonate) but weaker than lye (which may refer to sodium hydroxide or, lesscommonly, potassium hydroxide). Alkalinity impacts the synthesis of gluten inkneaded doughs and promotes browning by lowering the temperature at which theMaillard process takes place. To take advantage of the former effect,
It's utilised as a pH regulator, forexample, to keep the alkaline conditions required for the majority of photographicfilm developing chemicals stable. It's also a typical ingredient in swimmingpools and aquarium water to keep the pH and carbonate hardness in check (KH). Sodium Carbonate (also known as soda ash fixative or soda ashactivator) is used in dyeing with fiber-reactive dyes to promote correctchemical bonding of the dye with cellulose (plant) fibres, either before dyeing(for tie dyes), mixed with the dye (for dye painting), or after dyeing (forimmersion dyeing). It's also utilised as a float condition in the frothflotation process to keep a good pH.
Sodium Carbonate is a water-soluble mineral that can be found in dryareas, particularly in mineral deposits (evaporites) created when seasonallakes evaporate. Natron deposits have been mined from dry lake bottoms in Egyptsince ancient times, when the mineral was employed in the preparation ofmummies and the early production of glass.
The anhydrous mineral form of sodium-carbonate,known as natrite, is extremely rare. Sodium-carbonate also erupts fromTanzania's unique volcano, Ol Doinyo Lengai, and it is thought to have eruptedfrom other volcanoes in the past, although it is likely to have eroded due tothese minerals' instability at the earth's surface. Ultra-alkaline pegmatiticrocks, such as those found on Russia's Kola Peninsula, include all threemineralogical forms of Sodium Carbonate, as well as trona, trisodiumhydrogendicarbonate dihydrate.
Several "halophyte"(salt-tolerant) plant and seaweed species can be processed to produce an impureform of Sodium Carbonate, and this source dominated in Europe andelsewhere until the early nineteenth century. The seaweed (usually Fucusspecies) or land plants (often glassworts or saltworts) were gathered, dried,and burned. After that, the ashes were "lixivated" (washed in water)to create an alkali solution. This solution was dried and boiled to produce"soda ash"; this extremely old name comes from the Arabic word soda,which was then used to salsola soda, one of the several seashore plant speciesgathered for manufacturing.
Because of its low solubility, sodiumbicarbonate was collected as a precipitate and then heated to around 80 °C (176°F) or 95 °C (203 °F) to obtain pure Sodium Carbonate, comparable to theSolvay process's last stage. More sodium chloride is pumped into the residualammonium and sodium chlorides solution, as well as more ammonia at 30-40 °C.The temperature of the solution is then decreased to below 10 °C. At 30 °C,ammonium chloride has a higher solubility than sodium chloride, but at 10 °C,it has a lower solubility. Ammonium chloride precipitates in a sodium chloridesolution due to a temperature-dependent solubility differential and thecommon-ion effect.
