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SODIUM BICARBONATE

Sodium bicarbonate
Sodium bicarbonate
General
Systematic name Sodium hydrogen carbonate
Other names Sodium bicarbonate
bicarbonate of soda
Molecular formula NaHCO3
Molecular Weight 84.007 g/mol
Exact Mass 83.982
Appearance White crystalline solid.
CAS number [144-55-8] [1]
Properties
Density and phase 2.20 g/cm3, solid.
Solubility in water 10 g/100 ml (25°C)
Melting point 50°C (323.15 K)
Boiling point Decomposes.
Basicity (pKb)  ?
Structure
Molecular shape  ?
Coordination
geometry
 ?
Crystal structure  ?
Dipole moment  ? D
Hazards
MSDS External MSDS
Main hazards Irritant.
NFPA 704

0
1
0
 
Flash point Non-flammable.
R/S statement R: ?
S: ?
RTECS number VZ0950000
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Related compounds
Other anions Sodium carbonate
Other cations  ?
Related compounds Sodium hydrogen sulphate
sodium hydrogen phosphate
Except where noted otherwise, data are given for
materials in their standard state (at 25°C, 100 kPa)
Infobox disclaimer and references

Sodium bicarbonate NaHCO3, or sodium hydrogen carbonate, also known as baking soda, bread soda, or bicarbonate of soda, is a soluble white anhydrous or crystalline chemical compound, with a slight alkaline taste resembling that of sodium carbonate. It is found in many mineral springs and also produced artificially.

Sodium bicarbonate, when exposed to an acid, releases carbon dioxide and water:

NaHCO3 + HCl → NaCl + H2O + CO2 (gas)
NaHCO3 + CH3COOH → NaCH3COO + H2O + CO2 (gas)

Above 60°C, it gradually decomposes into sodium carbonate, water and carbon dioxide, and at 200°C it is completely decomposed into sodium carbonate:

2NaHCO3 → Na2CO3 + H2O + CO2

Contents

Common Uses

Sodium bicarbonate has many common uses:

  • It is used in combination with acidic compounds (such as cream of tartar, lemon juice, yoghurt, etc.) as a leavening agent in baking: some forms of baking powder contain sodium bicarbonate combined with cream of tartar. (Note: Some nutritionists, such as Erica White caution against combining with cream of tartar or tartaric acid, as they are toxic substances.)
  • Formerly, it was used as a source of carbon dioxide for soda water.
  • It is used as an antacid to treat acid indigestion and heartburn.
  • The anhydrous form is also used to absorb moisture and odours; an open box can be left in a refrigerator for this purpose. However, baking soda does not actually absorb odors well when used in a refrigerator (see [2])
  • Used in toothpaste, baking soda helps to gently remove stains, whiten teeth, freshen breath, and dissolve plaque.
  • Sodium bicarbonate is used as a fire-suppression agent ("BC powder") in some dry powder fire extinguishers. It is a minor component of Purple-K dry fire suppression agent.
  • It is commonly used to increase the pH and total alkalinity of the water for pools and spas. Sodium bicarbonate can be added as a simple solution for restoring the pH balance of water that has a high level of chlorine.

Sodium bicarbonate is also used in military applications. Cold sodium bicarbonate can be used to stop the chemical agent White Phosphorus, a common allotrope of phosphorus often used in incendiary bullets, from spreading inside a soldier's afflicted wounds. Military Application

Other Uses

The factual accuracy of this section is disputed.
Please see the relevant discussion on the talk page.

Baking soda has over a hundred uses. [3]

  • A paste from baking soda can be very effective when used in cleaning and scrubbing.
  • It removes coffee stains, marker, and crayon.
  • It can be used to clean out grease.
  • A solution in warm water will remove the tarnish from silver when the silver is in contact with a piece of aluminum foil.
  • With water, it cleans the impurities on contact lenses. Rinse completely before wearing contacts to avoid stinging of the salt in baking soda.
  • Baking soda and boiling water unclogs drains.
  • One cup of baking soda maintains a healthy septic tank. It controls pH and keeps a good environment for the bacteria.
  • If made into a paste salve, it relieves burning from bug stings, poison ivy, nettles, and sunburn.
  • Baking soda helps remove body odours as it absorbs chemicals, apply using a powder puff.
  • A teaspoon of it and a teaspoon of epsom salt in a glass of water cleans the blood stream. [citation needed]
  • It kills fleas and drives away ants. If it is applied to a pet's fur, it must be washed/rinsed off to prevent skin problems.
  • A small amount (1tsp) can be added to a beef stew to make tough meat tenderize faster. (However, this is no substitute for just stewing the meat for more time.)
  • It is used as a fabric softener in laundry.
  • It neutralizes battery acid.
  • It is used to test garden soil for acidity.
  • Can be used to kill crab grass in Florida St. Augustine grass. Must be used repeatedly to control but is effective. Dampen area then sprinkle lightly, too much may harm desired grass temporarily.
  • Sodium bicarbonate has been used as an endurance enhancer.

Safety

Although sodium bicarbonate can be used as an antacid, active dose amounts contain large amounts of sodium. Excess consumption can raise blood pH. Sodium bicarbonate should only be consumed in solution with water.

See also

Wikibooks
Wikibooks Cookbook has more about this subject:

External links