Sodium lime (Latin Natrium cum Calce, the old name — natristy lime, generic name — natroncalc) — mix of NaOH caustic soda and Ca (OH) 2 hydrated lime. Represents white porous weight.
Absorbs water (moisture from air) and carbon dioxide gas (CO2), passing into mix of carbonates: Na2CO3 sodium and calcium (calcite) of CaCO3.
For absorption of acid gases, for example carbon dioxide gas (CO2), including systems of the breath closed or half - closed, for example in gas masks, diving equipment. It is known that neutralization of the carbon dioxide gas emitted within a day by one person indoors of 6 m3, requires about 5 kg of absorber on the basis of sodium lime. Sodium lime cannot be regenerated owing to what too large reserves of lime are necessary for long stay of living beings in the closed space. In spaceships, for example, began to apply to carbonic acid binding cartridges with lithium hydroxide. Also sodium lime is used for artificial anesthesia in medicine. Sodium lime is applied in laboratory devices in organic analysis to definition of nitrogen on Vill and Varrentrapp's way, to carbonic acid absorption, instead of solution of caustic potassium, most often when burning in open tube on Marchand - Muldera's way.
For receiving sodium lime in vitro quicklime is extinguished concentrated solution of pure caustic soda, adding the last in number of 2 parts of CaO on 1 part of NaOH. Weight is evaporated dry in iron cup, poorly calcinated in iron or Giessen crucible, breaks into pieces and is sifted through sieve for the purpose of their sorting in size of grain and separation from trifle which is used too, for example when determining nitrogen in organic compounds on Varrentrapp and Vill's way. Sodium lime is stored in well closed vessels, otherwise it spoils, attracting moisture and carbonic acid from air. Quality of sodium lime can be defined: should not emit ammonia when calcinating with pure sugar that will indicate lack of nitrogenous and nitrate salts.
