|Jmol-3D images||Image 1|
|Molar mass||84.007 g mol−1|
|Density||2.20 g cm−3|
50 °C, 323 K, 122 °F (decomposes to sodium carbonate)
|Solubility in water||9 g/100 mL|
|Solubility||Soluble in acetone, insoluble in ethanol|
|Acidity (pKa)|| 10.329
6.351 (carbonic acid)
|Refractive index (nD)||1.3344|
| Routes of
| Std enthalpy of
| Standard molar
|Main hazards||Causes serious eye irritation|
|LD50||4.22 g kg−1|
|Other anions||Sodium carbonate|
|Other cations|| Ammonium bicarbonate|
|Related compounds|| Sodium bisulfate|
| (what is: / ?) |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula NaHCO3. 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. It is among the food additives encoded by European Union, identified by the initials E 500. Since 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. In colloquial usage, its name is shortened to sodium bicarb, bicarb soda, or simply bicarb. The word saleratus, from Latin sal æratus meaning aerated salt, was widely used in the 19th century for both sodium bicarbonate and potassium bicarbonate. The term has now fallen out of common usage.
- 1 History
- 2 Production
- 3 Mining
- 4 Chemistry
- 5 Applications
- 6 In popular culture
- 7 See also
- 8 References
- 9 Further reading
- 10 External links
In 1791, a French chemist, Nicolas Leblanc, produced sodium carbonate, also known as soda ash. In 1846, two New York bakers, John Dwight and Austin Church, established the first factory to develop baking soda from sodium carbonate and carbon dioxide.
This compound, referred to as saleratus, is mentioned in the famous novel Captains Courageous by Rudyard Kipling as being used extensively in the 1800s in commercial fishing to prevent freshly-caught fish from spoiling.
NaHCO3 is mainly prepared by the Solvay process, which is the reaction of sodium chloride, ammonia, and carbon dioxide in water. Calcium carbonate is used as the source of CO2 and the resultant calcium oxide is used to recover the ammonia from the ammonium chloride. The product shows a low purity (75 %). Pure product is obtained from sodium carbonate, water and carbon dioxide as reported in one of the following reactions. It is produced on the scale of about 100,000 tonnes/year (as of 2001).
- CO2 + 2 NaOH → Na2CO3 + H2O
Further addition of carbon dioxide produces sodium bicarbonate, which at sufficiently high concentration will precipitate out of solution:
- Na2CO3 + CO2 + H2O → 2 NaHCO3
Commercial quantities of baking soda are also produced by a similar method: soda ash, mined in the form of the ore trona, is dissolved in water and treated with carbon dioxide. Sodium bicarbonate precipitates as a solid from this method:
- Na2CO3 + CO2 + H2O → 2 NaHCO3
Naturally occurring deposits of nahcolite (NaHCO3) are found in the Eocene-age (55.8–33.9 Ma) Green River Formation, Piceance Basin in Colorado. Nahcolite was deposited as beds during periods of high evaporation in the basin. It is commercially mined using in-situ leach techniques involving dissolution of the nahcolite by heated water that is pumped through the nahcolite beds and reconstituted through a natural cooling crystallization process.
3 + H2O → Template:Chem/link + OH−
Sodium bicarbonate can be used as a wash to remove any acidic impurities from a "crude" liquid, producing a purer sample. Reaction of sodium bicarbonate and an acid produce a salt and carbonic acid, which readily decomposes to carbon dioxide and water:
- NaHCO3 + HCl → NaCl + H2CO3
- H2CO3 → H2O + CO2(g)
- NaHCO3 + CH3COOH → CH3COONa + H2O + CO2(g)
- NaHCO3 + NaOH → Na2CO3 + H2O
Sodium bicarbonate reacts with carboxyl groups in proteins to give a brisk effervescence from the formation of Template:Chem/link. This reaction is used to test for the presence of carboxylic groups in protein.
- 2 NaHCO3 → Na2CO3 + H2O + CO2
- Na2CO3 → Na2O + CO2
These conversions are relevant to the use of NaHCO3 as a fire-suppression agent ("BC powder") in some dry powder fire extinguishers.
Sodium bicarbonate is used in a process for removing paint and corrosion called sodablasting; the process is particularly suitable for cleaning aluminium panels which can be distorted by other types of abrasive. It can be administered to pools, spas, and garden ponds to raise pH levels. It has weak disinfectant properties, and it may be an effective fungicide against some organisms. Because baking soda will absorb musty smells, it has become a reliable method for used-book sellers when making books less malodorous.
Sodium bicarbonate can be used to extinguish small grease or electrical fires by being thrown over the fire. However, it should not be applied to fires in deep fryers, as it may cause the grease to splatter. Sodium bicarbonate is used in BC dry chemical fire extinguishers as an alternative to the more corrosive ammonium phosphate in ABC extinguishers. The alkali nature of sodium bicarbonate makes it the only dry chemical agent, besides Purple-K, that was used in large-scale fire suppression systems installed in commercial kitchens. Because it can act as an alkali, the agent has a mild saponification effect on hot grease, which forms a smothering soapy foam. Dry chemicals have since fallen out of favor for kitchen fires, as they have no cooling effect compared to the extremely effective wet chemical agents specifically designed for such hazards.
Sodium bicarbonate, referred to as "baking soda" is primarily used in cooking (baking), as a leavening agent. It reacts with acidic components in batters, releasing carbon dioxide, 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. Acidic compounds that induce this reaction include phosphates, cream of tartar, lemon juice, yogurt, buttermilk, cocoa, vinegar, etc. Sodium bicarbonate can be substituted for baking powder provided sufficient acid reagent is also added to the recipe. Many forms of baking powder contain sodium bicarbonate combined with calcium acid phosphate, sodium aluminum sulphate  or cream of tartar.
Sodium bicarbonate was sometimes used in cooking vegetables, to make them softer, although this has gone out of fashion, as most people now prefer firmer vegetables. However, it is still used in Asian cuisine to tenderise meats. Baking soda may react with acids in food, including Vitamin C (L-ascorbic acid). It is also used in breadings such as for fried foods to enhance crispness.
Heat causes sodium bicarbonate to act as a raising agent by releasing carbon dioxide when used in baking. The carbon dioxide production starts at temperatures above 80 °C. Since the reaction does not occur at room temperature, mixtures (cake batter, etc.) can be allowed to stand without rising until they are heated in the oven.
Neutralization of acids and bases
Many laboratories keep a bottle of sodium bicarbonate powder within easy reach, because sodium bicarbonate is amphoteric, reacting with acids and bases. Furthermore, as it is relatively innocuous in most situations, there is no harm in using excess sodium bicarbonate. Also, sodium bicarbonate powder may be used to smother a small fire, as heating of sodium bicarbonate releases carbon dioxide.
A wide variety of applications follows from its neutralization properties, including reducing the spread of white phosphorus from incendiary bullets inside an afflicted soldier's wounds.[medical citation needed]
Intravenous sodium bicarbonate is an aqueous solution that is sometimes used for cases of acidosis, or when there are insufficient sodium or bicarbonate ions in the blood. In cases of respiratory acidosis, the infused bicarbonate ion drives the carbonic acid/bicarbonate buffer of plasma to the left and, thus, raises the pH. It is for this reason that sodium bicarbonate is used in medically supervised cardiopulmonary resuscitation. Infusion of bicarbonate is indicated only when the blood pH is markedly (<7.1–7.0) low.
Oral sodium bicarbonate has been shown to slow progression to end stage renal disease in individuals with stage 4 chronic kidney disease and metabolic acidosis (plasma sodium bicarbonate levels 16-20meq/L). 
It is used as well for treatment of hyperkalemia. Since sodium bicarbonate can cause alkalosis, it is sometimes used to treat aspirin overdoses. Aspirin requires an acidic environment for proper absorption, and the basic environment diminishes aspirin absorption in the case of an overdose. Sodium bicarbonate has also been used in the treatment of tricyclic antidepressant overdose. It can also be applied topically as a paste, with three parts baking soda to one part water, to relieve some kinds of insect bites and stings (as well as accompanying swelling).
Adverse reactions to the administration of sodium bicarbonate can include metabolic alkalosis, edema due to sodium overload, congestive heart failure, hyperosmolar syndrome, hypervolemic hypernatremia, and hypertension due to increased sodium. In patients consuming a high-calcium or dairy-rich diet, calcium supplements, or calcium-containing antacids such as calcium carbonate (e.g., Tums), the use of sodium bicarbonate can cause milk-alkali syndrome, which can result in metastatic calcification, kidney stones, and kidney failure.
Bicarbonate of soda can also be useful in removing splinters from the skin.
Sodium bicarbonate is also used as an ingredient in some mouthwashes. It has anti-caries and abrasive properties. It works as a mechanical cleanser on the teeth and gums, neutralizes the production of acid in the mouth and also acts as an antiseptic to help prevent infections.
Small amounts of sodium bicarbonate have been shown to be useful as a supplement for athletes in speed-based events, like middle distance running, lasting from about one to seven minutes. However, overdose is a serious risk because sodium bicarbonate is slightly toxic; gastrointestinal irritation is of particular concern. Additionally, this practice causes a significant increase in dietary sodium.
As a cleaning agent
A paste from baking soda can be very effective when used in cleaning and scrubbing. For cleaning aluminium objects, the use of sodium bicarbonate is discouraged as it attacks the thin unreactive protective oxide layer of this otherwise very reactive metal. A solution in warm water will remove the tarnish from silver when the silver is in contact with a piece of aluminium foil. A paste of sodium bicarbonate and water is useful in removing surface rust as the rust forms a water soluble compound when in a concentrated alkaline solution. Cold water should be used as hot water solutions can corrode steel.
Baking soda is commonly added to washing machines as a replacement for softener and to remove odors from clothes. Sodium bicarbonate is also effective in removing heavy tea and coffee stains from cups when diluted with warm water.
During the Manhattan Project to develop the atomic bomb in the early 1940s, many scientists investigated the toxic properties of uranium. They found that uranium oxides stick very well to cotton cloth, but did not wash out with soap or laundry detergent. The uranium would wash out with a 2% solution of sodium bicarbonate (baking soda). Clothing can become contaminated with depleted uranium (DU) dust and normal laundering will not remove it. Those at risk of DU dust exposure should have their clothing washed with baking soda (about 6 ounces (170g) of baking soda in 2 gallons (7.5l) of water).
As a biopesticide
Cattle feed supplement
In popular culture
Sodium bicarbonate, as 'bicarbonate of soda', was a frequent source of punch lines for Groucho Marx in Marx brothers movies. In Duck Soup, Marx plays the leader of a nation at war. In one scene, he receives a message from the battlefield that his general is reporting a gas attack, and Groucho tells his aide, "Tell him to take a teaspoonful of bicarbonate of soda and a half a glass of water." In A Night at the Opera, Groucho's character addresses the opening night crowd at an opera by saying of the lead tenor, "Signor Lassparri comes from a very famous family. His mother was a well-known bass singer. His father was the first man to stuff spaghetti with bicarbonate of soda, thus causing and curing indigestion at the same time."
- Carbonic acid
- Baking powder
- List of ineffective cancer treatments
- List of minerals
- Natrona (disambiguation)
|Commons has media related to Sodium bicarbonate.|
|Cookbook has a recipe/module on Template:Plainlist|
- International Chemical Safety Card 1044
- Differences between Baking Soda and Baking Powder