Sodium bicarbonate or
sodium hydrogen carbonate is the
chemical compoundA chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the formula NaHCO
3. Sodium bicarbonate is a white solid that is
crystalA crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is crystallography...
line but often appears as a fine powder. It has a slight alkaline taste resembling that of washing soda (
sodium carbonateSodium carbonate , , is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate; and is domestically well known for its everyday use as a water softener...
). It is a component of the mineral
natronNatron is a naturally occurring mixture of sodium carbonate decahydrate and about 17% sodium bicarbonate along with small quantities of household salt and sodium sulfate...
and is found dissolved in many
mineral springMineral springs are naturally occurring springs that produce water containing minerals, or other dissolved substances, that alter its taste or give it a purported therapeutic value...
s. The natural mineral form is known as
nahcoliteNahcolite is a soft, colourless or white carbonate mineral with the composition of sodium bicarbonate also called thermokalite. It crystallizes in the monoclinic system....
. It is also produced artificially.
Since it has long been known and is widely used, the salt has many related names such as
baking soda,
bread soda,
cooking soda,
bicarbonate of soda. Colloquially, its name is shortened to
sodium bicarb,
bicarb soda, or simply
bicarb. The word
saleratus, from Latin
sal æratus meaning "aerated
saltA salt, in chemistry, is an ionic compound, and can result from the neutralization reaction of acids and bases. Salts are ionic compounds composed of cations and anions so that the product is electrically neutral...
", was widely used in the 19th century for both sodium bicarbonate and
potassium bicarbonatePotassium bicarbonate , is a colorless, odorless, slightly basic, salty substance...
. The term has now fallen out of common usage.
History
The ancient Egyptians used natural deposits of
natronNatron is a naturally occurring mixture of sodium carbonate decahydrate and about 17% sodium bicarbonate along with small quantities of household salt and sodium sulfate...
, a mixture consisting mostly of
sodium carbonateSodium carbonate , , is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate; and is domestically well known for its everyday use as a water softener...
decahydrate and sodium bicarbonate. The natron was used as a cleansing agent like
soapSoap is an anionic surfactant used in conjunction with water for washing and cleaning, which historically comes either in solid bars or in the form of a viscous liquid....
.
In 1791, a French chemist,
Nicolas LeblancNicolas Leblanc was a French chemist and surgeon who discovered how to manufacture soda from common salt.- Earlier days :...
, produced sodium bicarbonate as we know it today. In 1846 two New York bakers, John Dwight and Austin Church, established the first factory to develop baking soda from sodium carbonate and
carbon dioxideCarbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state...
.
Production
NaHCO
3 is mainly prepared by the
Solvay processThe Solvay process, also referred to as the ammonia-soda process, is the major industrial process for the production of soda ash . The ammonia-soda process was developed into its modern form by Ernest Solvay during the 1860s...
, which is the reaction of
calcium carbonateCalcium carbonate is a chemical compound with the chemical formula CaCO
3. It is a common substance found in rock in all parts of the world, and is the main component of shells of marine organisms, snails, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural...
,
sodium chlorideSodium chloride, also known as salt, common salt, table salt, or halite, is an ionic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
,
ammoniaAmmonia is a compound of nitrogen and hydrogen with the formula NH
3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers...
, and
carbon dioxideCarbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state...
in water. It is produced on the scale of about 100,000 ton/year (as of 2001).
NaHCO
3 may be obtained by the reaction of
carbon dioxideCarbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state...
with an aqueous solution of
sodium hydroxideSodium hydroxide , also known as lye and caustic soda, is a caustic metallic base. It is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Worldwide production in 1998 was around...
. The initial reaction produces
sodium carbonateSodium carbonate , , is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate; and is domestically well known for its everyday use as a water softener...
:
- CO2 + 2 NaOH → Na2CO3 + H2O
Further addition of
carbon dioxideCarbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state...
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
tronaTrona ; Na3H2·2H2O is an evaporite mineral. It is mined as the primary source of sodium carbonate in the United States, where it has replaced the Solvay process used in most of the rest of the world for sodium carbonate production.- Natural occurrence :Trona is...
, is dissolved in water and treated with carbon dioxide. Sodium bicarbonate precipitates as a solid from this method:
- Na2CO3 + CO2 + H2O → 2 NaHCO3
Mining
Naturally occurring deposits of nahcolite (NaHCO
3) are found in the
EoceneThe Eocene epoch, lasting from 55.8 ± 0.2 to 33.9 ± 0.1 Ma , is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. The Eocene spans the time from the end of the Paleocene epoch to the beginning of the Oligocene epoch. The start of the...
-age (55.8 ± 0.2 - 33.9 ± 0.1 Ma)
Green River FormationThe Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in winter. Each pair of layers is called a varve and...
,
Piceance BasinThe Piceance Basin is a geologic structural basin in northwestern Colorado, in the United States. It includes geologic formations from Cambrian to Holocene in age, but the thickest section is made up of rocks from the Cretaceous Period...
in
ColoradoColorado is a U.S. state located in the Rocky Mountain region of the United States of America. It may also be considered to be part of the Western and Southwestern regions of the United States. Colorado entered statehood in 1876 and was nicknamed the “Centennial State”...
. 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 which is pumped through the nahcolite beds and reconstituted through a natural cooling crystallization process.
Natural Soda, Inc., the only North American processor of natural sodium bicarbonate, is owned by AmerAlia (AALA) and The Sentient Group. The operation is located 54 miles northwest of
Rifle, ColoradoThe City of Rifle is a Home Rule Municipality in Garfield County, Colorado, United States. The population was 6,784 at the 2000 census. The town is a regional center of the cattle ranching industry located along Interstate 70 and the Colorado River just east of the Roan Cliffs, which dominate the...
. The Natural Soda facility has changed ownership several times over the last decade, proving difficult to turn a profit. All other North American producers base their production of sodium bicarbonate on
tronaTrona ; Na3H2·2H2O is an evaporite mineral. It is mined as the primary source of sodium carbonate in the United States, where it has replaced the Solvay process used in most of the rest of the world for sodium carbonate production.- Natural occurrence :Trona is...
found in the
Green River FormationThe Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in winter. Each pair of layers is called a varve and...
of
WyomingWyoming is a state in the Western United States. The majority of the state is dominated by the mountain ranges and rangelands of the Rocky Mountain West, while the easternmost section of the state includes part of a high elevation prairie region known as the High Plains. While the tenth largest...
.
Chemistry
Sodium bicarbonate is an amphoteric compound. Aqueous solutions are mildly alkaline due to the formation of
carbonic acidCarbonic acid has the formula H2CO3. It is also a name sometimes given to solutions of carbon dioxide in water, which contain small amounts of H2CO3. The salts of carbonic acids are called bicarbonates and carbonates. It is a weak acid...
and
hydroxideIn chemistry, hydroxide is the name for the diatomic anion OH−, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It is one of the simplest diatomic ions known....
ion:
- HCO + H2O → + 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
acidAn acid is traditionally considered any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion activity greater than in pure water, i.e. a pH less than 7.0...
to give a salt and carbonic acid, which readily decomposes to carbon dioxide and water:
- NaHCO3 + HCl → NaCl + H2CO3
- H2CO3 → H2O + CO2 (g)
Sodium bicarbonate reacts with
acetic acidAcetic acid, CH
3COOH, also known as ethanoic acid, is an organic acid which gives vinegar its sour taste and pungent smell. It is a weak acid, in that it is only partially dissociated acid in aqueous solution...
to form
sodium acetateSodium acetate, is the sodium salt of acetic acid. It is an inexpensive chemical produced in industrial quantities for a wide range of uses.-Industrial:...
:
- NaHCO3 + CH3COOH → CH3COONa + H2O + CO2 (g)
Sodium bicarbonate reacts with
baseIn chemistry, a base is most commonly thought of as an aqueous substance that can accept hydrogen ions. Bases are also the oxides or hydroxides of metals. A soluble base is also often referred to as an alkali if hydroxide ions are involved. This refers to the Brønsted-Lowry theory of acids and bases...
s such as
sodium hydroxideSodium hydroxide , also known as lye and caustic soda, is a caustic metallic base. It is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Worldwide production in 1998 was around...
to form
carbonateIn chemistry, a carbonate is a salt or ester of carbonic acid, characterized by the presence of the carbonate ion, or a carbonate functional group O=C2....
s:
- NaHCO3 + NaOH → Na2CO3 + H2O
Sodium bicarbonate reacts with
carboxyl groupA carboxyl group is a set of four atoms bonded together and present in carboxylic acids, including amino acids. Usually abbreviated as either CO2H or COOH, this set of atoms constitutes a functional group. In every carboxyl group the carbon atom is attached to an oxygen atom by a...
s in proteins to give a brisk effervescence from the formation of . This reaction is used to test for the presence of carboxylic groups in protein.
Thermal decomposition
Above 70 °C, sodium bicarbonate gradually decomposes into
sodium carbonateSodium carbonate , , is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate; and is domestically well known for its everyday use as a water softener...
,
waterWater is an ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71%...
and
carbon dioxideCarbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state...
. The conversion is fast at 250 °C:
- 2 NaHCO3 → Na2CO3 + H2O + CO2
Most bicarbonates undergo this
dehydration reactionIn chemistry, a dehydration reaction is usually defined as a chemical reaction that involves the loss of water from the reacting molecule. Dehydration reactions are a subset of elimination reactions...
. Further heating converts the carbonate into the
oxideSodium oxide is a chemical compound with the formula Na2O. It is used in ceramics and glasses. Treatment with water affords sodium hydroxide.The alkali metal oxides M2O crystallise in the antifluorite structure...
(at around 1000 °C):
- Na2CO3 → Na2O + CO2
These conversions are relevant to the use of NaHCO
3 as a fire-suppression agent ("BC powder") in some dry powder
fire extinguisherA fire extinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user , or otherwise requires the expertise of a fire...
s.
Cooking
Sodium bicarbonate is primarily used in
cookingCooking is the process of preparing food by applying heat, selecting, measuring and combining of ingredients in an ordered procedure for producing safe and edible food. The process encompasses a vast range of methods, tools and combinations of ingredients to alter the flavor, appearance, texture,...
(
bakingBaking is the technique of prolonged cooking of food by dry heat acting by convection, and not by radiation, normally in an oven, but also in hot ashes, or on hot stones. It is primarily used for the preparation of bread, cakes, pastries and pies, tarts, quiches, and cookies. Such items are...
) where it reacts with other components to release carbon dioxide, that helps
doughDough is a paste made out of any cereals or leguminous crops by mixing flour with a small amount of water and/or other liquid. This process is a precursor to making a wide variety of foodstuffs, particularly breads and bread-based items , including flatbreads, and pancakes, noodles, crusts,...
"rise". The acidic compounds that induce this reaction include phosphates, cream of tartar,
lemon juiceThe lemon is a small evergreen tree originally native to Asia, and is also the name of the tree's oval yellow fruit. The fruit is used for culinary and nonculinary purposes throughout the world – primarily for its juice, though the pulp and rind are also used, mainly in cooking and baking...
, yogurt,
buttermilkButtermilk refers to a number of deliciously tasting dairy drinks. Originally, buttermilk was the liquid left behind after churning butter out of cream. It also refers to a range of fermented milk drinks, common in warm climates where fresh milk would otherwise sour quickly. It is also popular in...
,
cocoaCocoa is the dried and fully fermented fatty seed of the cacao tree, from which chocolate is made. "Cocoa" can often also refer to the drink commonly known as hot chocolate; to cocoa powder, the dry powder made by grinding cocoa seeds and removing the cocoa butter from the dark, bitter cocoa...
,
vinegarVinegar is an acidic liquid processed from the fermentation of ethanol in a process that yields its key ingredient, acetic acid. It also may come in a diluted form. The acetic acid concentration typically ranges from 4 to 8 percent by volume for table vinegar and higher concentrations for pickling...
, etc. Sodium bicarbonate can be substituted for
baking powderBaking powder is a dry chemical leavening agent used to increase the volume and lighten the texture of baked goods such as muffins, cakes, scones and North American biscuits. Baking powder works by releasing carbon dioxide gas into a batter or dough through an acid-base reaction, causing bubbles in...
provided sufficient acid reagent is also added to the recipe. Many forms of baking powder contain sodium bicarbonate combined with one or more acidic phosphates (especially good) or cream of tartar. Can also be used for softening peas (⅛ tsp. per pint of water and bring to boil for one hour)
Thermal decomposition causes sodium bicarbonate alone to act as a raising agent by releasing carbon dioxide at baking temperatures. The mixture for cakes using this method can be allowed to stand before baking without any premature release of carbon dioxide.
Neutralization of acids and bases
Many laboratories keep a bottle of sodium bicarbonate powder within easy reach, because sodium bicarbonate is
amphotericIn chemistry, an amphoteric substance is one that can react as either an acid or base. The word is derived from the Greek prefix ampho- meaning "both"....
, reacting with
acids and basespH is a measure of the acidity or basicity of a solution. It is defined as the cologarithm of the activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations...
. Furthermore, as it is relatively innocuous in most situations, there is no harm in using excess sodium bicarbonate. Lastly, sodium bicarbonate powder may be used to smother a small fire.
A wide variety of applications follows from its neutralization properties, including ameliorating the effects of white phosphorus in incendiary bullets from spreading inside an afflicted soldier's wounds. Sodium bicarbonate can be added as a simple solution for raising the pH balance of water (increasing total alkalinity) where high levels of chlorine (2-5 ppm) are present as in swimming pools and aquariums.
Medical uses
Sodium bicarbonate is used in an
aqueous solutionAn aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending to the relevant formula. The word aqueous means pertaining to, related to, similar to, or dissolved in water...
as an
antacidAn antacid is any substance, generally a base or basic salt, which counteracts stomach acidity. In other words, antacids are stomach acid neutralizers.-Action mechanism:...
taken orally to treat
acid indigestionAcid indigestion is a type of indigestion involving an excess or possible lack of acid in the stomach. Frequent occurrence of acid indigestion can lead to aggravation of the duodenum or to an aggravation of the lining of the stomach, both of which can lead to ulcers which can be life-threatening...
and
heartburnHeartburn or pyrosis is a painful and burning sensation in the esophagus, just behind the breastbone usually associated with regurgitation of gastric acid. The pain often rises in the chest and may radiate to the neck, throat, or angle of the jaw...
. It may also be used in an oral form to treat chronic forms of metabolic acidosis such as
chronic renal failureChronic kidney disease , also known as chronic renal disease, is a progressive loss of renal function over a period of months or years. The symptoms of worsening kidney function are unspecific, and might include feeling generally unwell and experiencing a reduced appetite...
and
renal tubular acidosisRenal tubular acidosis is a medical condition that involves an accumulation of acid in the body due to a failure of the kidneys to appropriately acidify the urine. When blood is filtered by the kidney, the filtrate passes through the tubules of the nephron, allowing for exchange of salts, acid...
. Sodium bicarbonate may also be useful in urinary alkalinization for the treatment of aspirin overdose and
uric acidUric acid is an organic compound of carbon, nitrogen, oxygen and hydrogen with the formula C
5H
4N
4O
3.-Biology:...
renal stones.
An aqueous solution is sometimes administered intravenously for cases of
acidosisAcidosis is an increased acidity . If not further qualified, it usually refers to acidity of the blood plasma....
, 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 marked (<7.1-7.0) low.
It is used as well for treatment of
hyperkalemiaHyperkalemia is an elevated blood level of the electrolyte potassium. Extreme hyperkalemia is a medical emergency due to the risk of potentially fatal abnormal heart rhythms ....
. Since sodium bicarbonate can cause
alkalosisAlkalosis refers to a condition reducing hydrogen ion concentration of arterial blood plasma . Generally alkalosis is said to occur when pH of the blood exceeds 7.45...
, it is sometimes used in 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 overdoseTricyclic antidepressant overdose is caused by excessive use or overdose of a tricyclic antidepressant drug. It is a significant cause of fatal drug poisoning. The severe morbidity and mortality associated with these drugs is well documented due to their cardiovascular and neurological toxicity...
. It can also be applied topically as a paste, with three parts baking soda to one part water, to relieve insect bites.
Adverse reactions to the administration of sodium bicarbonate can include
metabolic alkalosisMetabolic alkalosis is a metabolic condition in which the pH of the blood is elevated beyond the normal range . This is usually the result of decreased hydrogen ion concentration, leading to increased bicarbonate, or alternatively a direct result of increased bicarbonate...
,
edemaEdema or oedema , formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin, or in one or more cavities of the body...
due to sodium overload,
congestive heart failureHeart failure is a condition in which a problem with the structure or function of the heart impairs its ability to supply sufficient blood flow to meet the body's needs...
,
hyperosmolar syndromeHyperosmolar syndrome or diabetic hyperosmolar syndrome is a medical emergency caused by a very high blood glucose level.The prefix "hyper" means high, and "osmolarity" is a measure of the concentration of active particles in a solution, so the name of the syndrome simply refers to the high...
, hypervolemic
hypernatremiaHypernatremia or hypernatraemia is an electrolyte disturbance that is defined by an elevated sodium level in the blood. Hypernatremia is generally not caused by an excess of sodium, but rather by a relative deficit of free water in the body...
, and
hypertensionHypertension is a chronic medical condition in which the blood pressure is elevated. It is also referred to as high blood pressure or shortened to HT, HTN or HPN. The word "hypertension", by itself, normally refers to systemic, arterial hypertension.Hypertension can be classified as either...
due to increased sodium. In patients who consume a high calcium or dairy-rich diet, calcium supplements, or calcium-containing antacids such as
calcium carbonateCalcium carbonate is a chemical compound with the chemical formula CaCO
3. It is a common substance found in rock in all parts of the world, and is the main component of shells of marine organisms, snails, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural...
(e.g., Tums), the use of sodium bicarbonate can cause
milk-alkali syndromeIn medicine, milk-alkali syndrome, also called Burnett's syndrome in honour of Charles Hoyt Burnett, the American physician who first described it, is characterized by hypercalcemia caused by repeated ingestion of calcium and absorbable alkali...
, which can result in
metastatic calcificationMetastatic calcification is deposition of calcium salts in otherwise normal tissue, because of elevated serum levels of calcium in blood, which can occur because of deranged metabolism as well as increased absorption or decreased excretion of calcium and related minerals.It occurs as opposed to...
, kidney stones, and kidney failure.
Sodium bicarbonate is also used as an ingredient in some mouthwashes. It works as a mechanical cleanser on the teeth and gums, neutralizes the production of acid in the mouth and also as an antiseptic to help prevent infections occurring.
Personal hygiene
A paste made from sodium bicarbonate and a 3%
hydrogen peroxideHydrogen peroxide is a very pale blue liquid, slightly more viscous than water, that appears colorless in dilute solution. It is a weak acid, has strong oxidizing properties, and is a powerful bleaching agent. It is used as a disinfectant, antiseptic, oxidizer, and in rocketry as a propellant...
solution can be used as an alternative to commercial non-fluoride
toothpasteToothpaste is a paste or gel dentifrice used with a toothbrush to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it can aid in the removal of dental plaque and food from the teeth, aid in the elimination and/or masking of halitosis and deliver...
s, and sodium bicarbonate in combination with other ingredients can be used to make a dry or wet
deodorantDeodorants are substances applied to the body mainly to reduce body odor which is caused by the bacterial breakdown of perspiration. A subgroup of deodorants are "antiperspirants", which prevent odor and reduce sweat produced by parts of the body...
. Sodium bicarbonate is a common ingredient in alternative and natural brands of toothpaste and deodorant. It can be used as a treatment for
dandruffDandruff is the excessive shedding of dead skin cells from the scalp. Dandruff can also be caused by frequent exposure to extreme heat and cold. As it is normal for skin cells to die and flake off, a small amount of flaking is normal and in fact quite common...
due to its anti-fungal properties.
Soda loading
Sodium bicarbonate has been shown to be useful as a supplement for endurance athletes
As a cleaning agent
A paste from baking soda can be very effective when used in cleaning and scrubbing. For cleaning aluminium objects, sodium bicarbonate is to be discouraged as it attacks the thin unreactive protective oxide layer of this otherwise very reactive metal. A solution in warm water will remove the
tarnishTarnish is a layer of corrosion that forms over copper, brass, silver, aluminum, and other semi-reactive metals as they undergo oxidation. It is analogous to rust, but with a slower rate of occurrence. Tarnish is mainly caused by chemicals in the air, such as sulfur...
from
silverSilver is a chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
when the silver is in contact with a piece of
aluminium foilAluminium foil is aluminium prepared in thin metal leafs, with a thickness less than 0.2 mm / 0.008 in, although much thinner gauges down to 0.006 mm are commonly used.Foils are commonly gauged in Mils. The foil is extremely pliable, and can be bent or wrapped around objects with ease...
.
Baking soda is commonly added to the rinse cycles of washing machines (together with the detergent) as a replacement for softener and also to remove odors. Sodium bicarbonate is also effective in removing heavy tea and coffee stains from cups when diluted with warm water.
Miscellaneous
Sodium bicarbonate can be used to extinguish small grease or electrical fires by being poured or dumped over the fire. However, it should not be poured or dumped onto 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 phosphateAmmonium phosphate is the salt of ammonia and phosphoric acid. It has the molecular formula 3PO4 and consists of ammonium cations and phosphate anion...
in ABC extinguishers. The alkali nature of sodium bicarbonate makes it the only dry chemical agent, besides
Purple-KPurple-K is a dry chemical fire suppression agent used in some dry powder fire extinguishers. It is the most effective dry chemical in fighting class B fires, and can be used against some energized electrical equipment fires...
, 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 is used in a process for cleaning paint called
sodablastingSodablasting is a process where sodium bicarbonate is applied against a surface using compressed air. It was first used to restore the Statue of Liberty....
. It can be administered to pools, spas, and garden ponds to raise
pHpH is a measure of the acidity or basicity of a solution. It is defined as the cologarithm of the activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations...
levels. It has disinfectant and
antisepticAntiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...
properties, and it may be an effective
fungicideFungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in agriculture and to fight fungal infections in animals...
against some organisms.
Because it can be used to absorb odors, it is a tried-and-true method of used booksellers. The baking soda will absorb the musty smell, leaving the books less odorous.
See also
- Carbonic acid
Carbonic acid has the formula H2CO3. It is also a name sometimes given to solutions of carbon dioxide in water, which contain small amounts of H2CO3. The salts of carbonic acids are called bicarbonates and carbonates. It is a weak acid...
- Baking powder
Baking powder is a dry chemical leavening agent used to increase the volume and lighten the texture of baked goods such as muffins, cakes, scones and North American biscuits. Baking powder works by releasing carbon dioxide gas into a batter or dough through an acid-base reaction, causing bubbles in...
- List of minerals
- Nahcolite
Nahcolite is a soft, colourless or white carbonate mineral with the composition of sodium bicarbonate also called thermokalite. It crystallizes in the monoclinic system....
- Natron
Natron is a naturally occurring mixture of sodium carbonate decahydrate and about 17% sodium bicarbonate along with small quantities of household salt and sodium sulfate...
- Natrona
Natrona may refer to:In Pennsylvania:* Natrona, Pennsylvania, United States* Natrona Heights, Pennsylvania, United States* Harrison Township, Allegheny County, Pennsylvania, United StatesIn Illinois:* Natrona, Illinois, United States...
(disambiguation)
- Trona
Trona ; Na3H2·2H2O is an evaporite mineral. It is mined as the primary source of sodium carbonate in the United States, where it has replaced the Solvay process used in most of the rest of the world for sodium carbonate production.- Natural occurrence :Trona is...
External links