Natrijum hidrogenkarbonat

Natrijum hidrogenkarbonat

Ball and stick model of a sodium cation Ball and stick model of a bicarbonate anion
Nazivi
IUPAC naziv Natrijum vodonik karbonat
Drugi nazivi Prašak za pecivo, bikarb (laboratorijski sleng), bikarbonatna soda, nahkolit
Identifikacija
CAS broj	144-55-8 Y
3D model (Jmol)	interaktivna slika
Bajlštajn	4153970
ChEBI	CHEBI:32139 Y
ChemSpider	8609 Y
DrugBank	DB01390 Y
ECHA InfoCard	100.005.122
EC broj	205-633-8
E-brojevi	E500(ii) (regulator kiselosti, ...)
IUPHAR/BPS	4507
KEGG	C12603 Y
MeSH	Sodium+bicarbonate
PubChem C ID	516892
RTECS	VZ0950000
UNII	8MDF5V39QO Y
SMILES [Na+].OC([O-])=O
Svojstva
Hemijska formula	NaHCO 3
Molarna masa	84,0066 g mol−1
Agregatno stanje	Beli kristali
Miris	bez mirisa
Gustina	2,20 g/cm3
Tačka topljenja	(razlaže se na natrijum karbonat počevši od 50 °C)
Rastvorljivost u vodi	69 g/L (0 °C) 96 g/L (20 °C) 165 g/L (60 °C)
Rastvorljivost	0,02 tež.% aceton, 2,13 tež.% metanol @22 °C. nerastvoran u etanolu
log P	−0,82
Kiselost (pKa)	10,329 6,351 (ugljena kiselina)
Indeks refrakcije (nD)	nα = 1,377 nβ = 1,501 nγ = 1,583
Struktura
Kristalna rešetka/struktura	Monoclinic
Termohemija
Specifični toplotni kapacitet, C	87.6 J/mol K
Standardna molarna entropija So298	101.7 J/mol K
Std entalpija formiranja (ΔfH⦵298)	−950.8 kJ/mol
Gibsova slobodna energija (ΔfG˚)	−851.0 kJ/mol
Farmakologija
ATC kod	B05CB04 (WHO) B05XA02, QG04BQ01
Načini upotrebe	Intravenous, oral
Opasnosti
Opasnost u toku rada	Uzrokuje ozbilju iritaciju oka
NFPA 704	0 0 1
Tačka paljenja	Incombustible
Letalna doza ili koncentracija (LD, LC):
LD50 (LD50)	4220 mg/kg (pacov, oralno)
Srodna jedinjenja
Drugi anjoni	Natrijum karbonat
Drugi katjoni	Amonijum bikarbonat Kalijum bikarbonat
Srodna jedinjenja	Natrijum bisulfat Natrijum hidrogen fosphat
Ukoliko nije drugačije napomenuto, podaci se odnose na standardno stanje materijala (na 25 °C [77 °F], 100 kPa).
Y verifikuj (šta je YН ?)
Reference infokutije

Pečeni kapkejkovi soda bikarbonom kao sredstvom za podizanje

Natrijum hidrogenkarbonat, soda-bikarbona ili natrijum bikarbonat (IUPAC ime: natrijum vodonik karbonat, NaHCO₃) je beli prah koji je slabo rastvorljiv u vodi. It is a salt composed of a sodium cation (Na⁺) and a bicarbonate anion (HCO₃⁻). Sodium bicarbonate is a white solid that is crystalline, but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). The natural mineral form is nahcolite. It is a component of the mineral natron and is found dissolved in many mineral springs.

Nomenklatura

Because it has long been known and is widely used, the salt has many related names such as baking soda, bread soda, cooking soda, and bicarbonate of soda. The term baking soda is more common in the United States, whereas bicarbonate of soda is more common in Australia and Britain. In colloquial usage, the names sodium bicarbonate and bicarbonate of soda are often truncated; forms such as sodium bicarb, bicarb soda, bicarbonate, and bicarb are common.

The word saleratus, from Latin sal æratus (meaning "aerated salt"), was widely used in the 19th century for both sodium bicarbonate and potassium bicarbonate.

It is known as one of the E number food additives E500.

The prefix bi in bicarbonate comes from an outdated naming system and is based on the observation that there is twice as much carbonate (CO₃) per sodium in sodium bicarbonate (NaHCO₃) as there is in sodium carbonate (Na₂CO₃). The modern chemical formulas of these compounds express their precise chemical compositions (which were unknown when the names sodium carbonate and sodium bicarbonate were coined) as sodium hydrogen carbonate (NaHCO₃) and sodium carbonate (Na₂CO₃). These names are unambiguous since sodium always has the +1 oxidation state and carbonate the −2 oxidation state.

Hemijske osobine

Rastvor natrijum bikarbonata reaguje slabo bazno zbog hidrolize.

To je jedan od aditiva kodiran od strane Evropske unije, identifikovan inicijalima E500.

Rastvoren u vodi daje baznu sredinu. Reaguje sa kiselinama i tako razblažen, oslobađa vodu i ugljen-dioksid.

$NaHCO_{3}+HCl\rightarrow NaCl+H_{2}O+CO_{2}(g)$

$NaHCO_{3}+CH_{3}COOH\rightarrow CH_{3}COONa+H_{2}O+CO_{2}(g)$

Zbog svoje sposobonsti da reaguje sa kiselinama, koristi se i u farmaceutskoj industriji kao antacid i protiv gorušice.

Prekomernu upotrebu treba izbegavati, jer utiče na pH vrednost želuca. Višak natrijuma povećava krvni pritisak (povećava rizik od hipertenzije i edema).

Dobijanje

Osim Solvejevog postupka, soda bikarbona se dobija i uvođenjem CO₂ u vodeni rastvor natrijum karbonata.

Upotreba

Koristi se u proizvodnji praška za pecivo, u kozmetici, i proizvodnji penušavih pića.

Kuvanje

Narastanje

In cooking, baking soda is primarily used in baking as a leavening agent. When it reacts with acid, carbon dioxide is released, which causes expansion of the batter and forms the characteristic texture and grain in pancakes, cakes, quick breads, soda bread, and other baked and fried foods. The acid-base reaction can be generically represented as follows:

NaHCO₃ + H⁺ → Na⁺ + CO₂ + H₂O

Acidic materials that induce this reaction include hydrogen phosphates, cream of tartar, lemon juice, yogurt, buttermilk, cocoa, and vinegar. Baking soda may be used together with sourdough, which is acidic, making a lighter product with a less acidic taste.

Heat can also by itself cause sodium bicarbonate to act as a raising agent in baking because of thermal decomposition, releasing carbon dioxide at temperatures above 80 °C (180 °F), as follows:

2 NaHCO₃ → Na₂CO₃ + H₂O + CO₂

When used this way on its own, without the presence of an acidic component (whether in the batter or by the use of a baking powder containing acid), only half the available CO₂ is released (one CO₂ molecule is formed for every two equivalents of NaHCO₃). Additionally, in the absence of acid, thermal decomposition of sodium bicarbonate also produces sodium carbonate, which is strongly alkaline and gives the baked product a bitter, "soapy" taste and a yellow color. Since the reaction occurs slowly at room temperature, mixtures (cake batter, etc.) can be allowed to stand without rising until they are heated in the oven.

When adding acid, alkaline ingredients such as whole milk or Dutch-processed cocoa are often added to baked foods to avoid an over-acidic taste from the added acid.

Prašak za pecivo

Glavni članak: Prašak za pecivo

Prašak za pecivo, also sold for cooking, contains around 30% of bicarbonate, and various acidic ingredients which are activated by the addition of water, without the need for additional acids in the cooking medium. Many forms of baking powder contain sodium bicarbonate combined with calcium acid phosphate, sodium aluminium phosphate, or cream of tartar. Baking soda is alkaline; the acid used in baking powder avoids a metallic taste when the chemical change during baking creates sodium carbonate.

Drugo

Sodium bicarbonate was sometimes used in cooking green vegetables, as it gives them a bright green colour—which has been described as artificial-looking—due to its reacting with chlorophyll to produce chlorophyllin. However, this tends to affect taste, texture and nutritional content, and is no longer common.

Vidi još

• Natrijum karbonat

Spoljašnje veze

• Sporedne namene sode bikarbone („B92“, 20. jun 2011)