Sodium Bicarbonate is an inorganic compound with the chemical formula NaHCO3. It is found in nature in the form of nahcolite minerals. It is found dissolved in many mineral springs across the world. It is commonly called as baking soda or cooking soda, and sometimes as bicarbonate of soda. Sodium bicarbonate has been used by mankind from as early as the ancient Egyptian civilization. They used to use a mineral called natron, which consisted of sodium bicarbonate, for cleansing purposes. It was, however, industrially produced starting from 1846, by two New York bakers, who established a factory to develop baking soda from sodium carbonate and carbon dioxide. Pure product is obtained from the reaction of sodium carbonate, water and carbon dioxide.
General Properties of Sodium Bicarbonate are:
- It is odourless
- Has a slightly salty, alkaline taste
- It is neither flammable nor explosive
- It is soluble in water
- It is non volatile
Manufacturing Process of Sodium Bicarbonate
It is commercially prepared by Solvay process and involves the reaction of sodium chloride, ammonia, and carbon dioxide in water. To obtain a relatively low purity product, calcium carbonate is used as the carbon di oxide source and the resultant calcium oxide is used to recover the ammonia from the ammonium chloride.
The first reaction of the process is as indicated below:
NaCl + CO2 + NH3 + H2O → NaHCO3 + NH4Cl (I)
The Carbon dioxide is passed through a concentrated aqueous solution of sodium chloride and ammonia. This reaction is carried out in two packed towers.
Sodium bicarbonate has a wide range of applications, which include its use in food, cosmetics, pharmaceuticals, and industrial applications. It can be used as a pH regulator, for the release of CO2 and as a mild abrasive. The following are the applications of Sodium bicarbonate in various industries.
- Sodium Bicarbonate is used in cooking as a leavening agent as it reacts with acidic components in batters, releasing carbon dioxide, which causes the expansion of the batter and forms the characteristic texture and grain in baked and fried foods.
- It is used in cuisines to tenderise meats.
- It is used in fried foods to enhance the crispness.
- Sodium bicarbonate reduces stomach acid. It is used as an antacid to treat heartburn, indigestion, and upset stomach. Sodium bicarbonate is a very quick-acting antacid. However, it is only used for temporary relief.
- It is used for treatment of hyperkalemia. It is used to treat aspirin overdoses since sodium bicarbonate can cause alkalosis, and the acidic environment helps in the absorption of aspirin.
- It can be used in removing splinters from the skin.
- It has also been used to treat an overdose of tricyclic antidepressant.
- Sodium bicarbonate can be used as a cleansing agent to remove surface rust.
- It can be used to remove tarnish from silver.
- It is also used for washing clothes in replacement to softener.
- It is used as a bio pesticide as it can control the growth of fungus.
- It is used in the military/army to reduce the spread of white phosphorus from incendiary bullets inside an afflicted soldier’s wounds.
- It can be used to extinguish small grease or electrical fires by being thrown over the fire.
- It is used as a cattle feed supplement as it acts as a buffering agent.
- It is in toothpastes and mouthwashes for better whitening and plaque removal.
- It is used in wet and dry deodorants, in shampoos, etc.
|CAS NO.||: 144-55-8|
|MOL WT.||: 84.01|
|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)||: 150ppm, max|
|Matter insoluble in water||: 0.10 %, max|
|Sulphates (as SO4)||: 150ppm, 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||: 270C|
|BOILING POINT||: Cannot be determines as it decomposes over 50 C|
|SOLUBILITY IN WATER||: Soluble to 100mM in water|
|DENSITY AND PHASE||: 2.159 g/cm³, solid.|