Sodium bicarbonate

Sodium bicarbonate.
(also known as sodium hydrogencarbonate, bicarbonate of soda, Baking soda, nahcolite).

Chemical formula : NaHCO₃
(Na 27,37 %, C 14,3 %, H 1,2 %)

Molar mass = 84,0066 ± 0,0018 g·mol^-1

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);
it is the sodium salt of carbonic acid [CO3, H2O]. Also, this should not be confused with salt Caustic soda NaOH,

Production (natural) :
Sodium bicarbonate can be obtained from natron* deposits.
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
*evaporite rock containing sodium bicarbonate (NaHCO3) and sodium carbonate decahydrate (Na2CO3·10H2O).

Synthetic product.
NaHCO3 is mainly prepared by the Solvay process (1870) which produces sodium carbonate from salt and chalk supplanted Leblanc process (developed in 1789) as cleaner and less expensive.

Main Features :

	Anhydrous product
% NaHCO3	97 to 99%
Volumetric mass density (20°C)	2220 kg/m3
Melting point	50°C (decomposes to sodium carbonate)
Maximum solubility	96 g/L

Solubility in water (soft) as a function of temperature (in weight % of Na2CO3):

(in g NaHCO3 per 100 g)

Solution at 50 g/liter :

• Density = 1.045 g/L (1045 kg/m3)
• pH = 10.3
  
  with, pH = 1/2(pKe+pKa₂)+ 1/2log C
  where,
  pKe=14
  pKa=10.3,
  C=0.4717 M

A formulation for water treatment.
Reaction mechanism of lime with aggressive CO2 (simplified equations):
NaHCO₃ + CO₂ + H₂O >>> 2 NaHCO₃
....84............44 .....................2x84 or[100 mg/L as CaCO3 (10°F<TAC)]

In this case there is a constancy of the CO2 content of free water: transformation of aggressive CO2 in balancing CO2, forming NaHCO3, thus increasing the alkalinity (you can go up the balance of CaCO3 saturation ).

Thus to "transform" 1 mg aggressive CO2 must (84/44) = 1.91 mg of NaHCO3, which reforms (168/44) = 3.82 mg of sodium bicarbonate NaHCO3, and therefore also the "transformation" 1 mg/L in one aggressive CO2 form balancing CO2 (10/44) = 0.2273 ° F /L of TAC [2.273 mg/L as CaCO3] or the injection of 1 mg/L of NaHCO3 reform 0.119 ° F /L TAC [1.19 mg/L as CaCO3].

Note: if the calculated dose is a reagent for 100% purity, it is necessary to correct this dose to entering the purity of the commercial product.

Standardization.
Standard products used for the production of drinking water: French Official Bulletin - sodium bicarbonate : NF EN 898.

Uses.
Baking sode makes many services for the maintenance of machine and home, but also for hygiene, body care and kitchen (refreshes carpet cleaner and deodorizer).

• water remineralization, water neutralization
• aluminum anodizing
• smoke purification
• water softener
• It can be used to extinguish a fire when water use is not recommended. For example, for grease fires (used in some dry powder fire extinguishers)
• It blocks the development of mite allergens acari (Dermatophagoides pteronyssinus and D. farinae) - 20 g / m² powder on carpets, carpeting and mattresses
• Garden Fungicide (to fight against mildew for example) and used against ants in solution and in large quantities (more than 3 liters or two standard bottles) to be paid in the anthill.

Hygiene and health.
Sodium bicarbonate is biodegradable, and is not toxic to the environment or to health.

• cleanses the skin depth (scrub): make a paste with baking soda and three volumes of a volume of water)
• softens calluses and reduces itching caused by athlete's foot - attention, athlete's foot is a fungal infection
• used for gargling
• calms the stomach
• calm eczema (a half-cup of baking soda in a hot bath 15 to 20 minutes)
• calm sunburn with gauze soaked in a solution made ??with a tablespoon of sodium bicarbonate in 25 ml water
• also used for cold sores, sore gums, sore throat, fungal infections, insect bites and warts

Note: Quebec (Canada), in common parlance, it may sometimes be called "little cow". This is due to the small cow shown in boxes sodium bicarbonate sold by the company Cow Brand, there is so many years.

Sources : personal and Wikipedia, the free encyclopedia.

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