Sodium bicarbonate (NaHCO3) is a white crystalline powder commonly known to as baking soda. It is classified as an acid salt, formed by combining an acid (carbonic) and abase (sodium hydroxide), and it reacts with other chemicals as a mild alkali. At temperatures above 300°F (149°C), sodium bicarbonate decomposes into sodium carbonate (a more stable substance), water, and carbon dioxide.
In addition to its many home uses, sodium bicarbonate also has many industrial applications. For instance, sodium bicarbonate releases carbon dioxide when heated. Since carbon dioxide is heavier than air, it can smother flames by keeping oxygen out, making sodium bicarbonate a useful agent in fire extinguishers. Other applications include air pollution control (because it absorbs sulfur dioxide and other acid gas emissions), abrasive blastings for removal of surface coatings, chemical manufacturing, leather tanning, oil well drilling fluids (because it precipitates calcium and acts asa lubricant), rubber and plastic manufacturing, paper manufacturing, textile processing, and water treatment (because it reduces the level of lead and other heavy metals).
The native chemical and physical properties of sodium bicarbonate account for its wide range of applications, including cleaning, deodorizing, buffering, and fire extinguishing. Sodium bicarbonate neutralizes odors chemically, rather than masking or absorbing them. Consequently, it is used in bath salts and deodorant body powders. Sodium bicarbonate tends to maintain a pH of 8.1 (7 is neutral) even when acids, which lower pH, or bases, which raise pH, are added to the solution. Its ability to tabletize makes it a good effervescent ingredient in antacids and denture cleaning products. Sodium bicarbonate is also found in some anti-plaque mouthwash products and toothpaste. When sodium bicarbonate is used as a cleaner in paste form or dry on a damp sponge, its crystalline structure provides a gentle abrasion that helps to remove dirt without scratching sensitive surfaces. Its mild alkalinity works to turn up fatty acids contained in dirt and grease into a form of soap that can be dissolved in water and rinsed easily. Sodium bicarbonate is also used as a leavening agent in making baked goods such as bread or pancakes. When combined with an acidic agent (such as lemon juice), carbon dioxide gas is released and is absorbed by the product’s cells. As the gas expands during baking, the cell walls expand as well, creating a leavened product.
Sodium bicarbonate is primarily used in cooking ( baking ) where it reacts with other components to release carbon dioxide, that helps dough “rise”. The 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 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 amphoteric , reacting with acids and bases . 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.
Sodium bicarbonate is used in an aqueous solution as an antacid taken orally to treat acid indigestion and heartburn . It may also be used in an oral form to treat chronic forms of metabolic acidosis such as chronic renal failure and renal tubular acidosis . Sodium bicarbonate may also be useful in urinary alkalinization for the treatment of aspirin overdose and uric acid renal stones.
An aqueous solution is sometimes administered intravenously 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 marked (<7.1-7.0) low.
It is used as well for treatment of hyperkalemia . Since sodium bicarbonate can cause alkalosis , 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 overdose . 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 alkalosis , edema due to sodium overload, congestive heart failure , hyperosmolar syndrome , hypervolemic hypernatremia , and hypertension due to increased sodium. In patients who consume 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 .
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.
A paste made from sodium bicarbonate and a 3% hydrogen peroxide solution can be used as an alternative to commercial non-fluoride toothpastes , and sodium bicarbonate in combination with other ingredients can be used to make a dry or wet deodorant . Sodium bicarbonate is a common ingredient in alternative and natural brands of toothpaste and deodorant. It can be used as a treatment for dandruff due to its anti-fungal properties. [ citation needed ]
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 tarnish from silver when the silver is in contact with a piece of aluminium foil .
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.
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 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. [ citation needed ]
Sodium bicarbonate is used in a process for cleaning paint called sodablasting . It can be administered to pools, spas, and garden ponds to raise pH levels. It has disinfectant and antiseptic properties, and it may be an effective fungicide 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.
|CAS NO.||: 144-55-8|
|MOL WT.||: 83.982|
|TOXICITY||: LD 50: 5 g/kg (oral in rats)|
|SYNONYMS||: Sodium bicarbonate, Bicarbonate of soda, Baking soda|
|PHYSICAL AND CHEMICAL PROPERTIES|
|Total alkalinity (as NaHCO3)||: 99.20 %, min|
|pH||: 8.8 max|
|Chlorides (as Cl)||: 0.06 %, max|
|Matter insoluble in water||: 0.10 %, max|
|Sulphates (as SO4)||: 0.07 %, max|
|Iron (as Fe)||: 0.004 %, max|
|Heavy metals (as Pb)||: 5 ppm, max|
|Arsenic (as As)||: 1.5 ppm, max|
|Copper (as Cu)||: 30 ppm, max|
|PHYSICAL STATE||: White crystalline solid.|
|MELTING POINT||: Decomposes below MP|
|BOILING POINT||: Unknow>Decomposes|
|SOLUBILITY IN WATER||: 7.8g/100ml water @ 18C (64F)|
|Density and phase||: 2.159 g/cm³, solid.|
|DESCRIPTION OF SODIUM BICARBONATE|
Sodium bicarbonate is the chemical compound with the formula NaHCO3. Because it has long been known and is widely used, the salt has many other names including sodium hydrogencarbonate, sodium bicarb, baking soda, bread soda, cooking soda, bicarb soda, saleratus or bicarbonate of soda. It is soluble in water. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slight alkaline taste resembling that of sodium carbonate. It is a component of the mineral neutron and is found dissolved in many mineral springs. The natural mineral form is known as nahcolite. It is also produced artificially.