Sodium carbonate occurs naturally as the mineral natron and is produced commercially via the Solvay process. It crystallizes in different hydrated forms and is highly soluble in water. Sodium carbonate is used to neutralize acids, in glassmaking, and has various medical uses as an antacid and in preparing baths and solutions to treat skin conditions. The Solvay process uses salt water, limestone, and ammonia to produce sodium carbonate in a more economical way than the previous Leblanc process.

2.  Sodium carbonate (also known as washing soda, soda ash and soda
crystals, and in the monohydrate form as crystal carbonate), Na2CO3, is
the water-soluble Di sodium salt of carbonic acid.
Sodium carbonate crystallizes from water to form three different hydrates:
 sodium carbonate decahydrate (natron), Na2CO3·10H2O. (Washing soda)
 sodium carbonate heptahydrate (not known in mineral form),
Na2CO3·7H2O.
 sodium carbonate monohydrate (thermonatrite), Na2CO3·H2O
 anhydrous sodium carbonate also known as Soda Ash.

3.  Sodium carbonate occur naturally in arid regions,
especially in mineral deposits (evaporites) formed
when seasonal lakes evaporate. Deposits of the
mineral natron have been mined from dry lake
bottoms in Egypt since ancient times, when natron
was used in the preparation of mummies and in the
early manufacture of glass.

4.  The anhydrous mineral form of sodium carbonate is quite
rare and called natrite. Sodium carbonate also erupts from
Doinyo
 Doinyo Lengai is unique among active volcanoes in that it
produces natrocarbonatite lava, a unique occurrence of
volcanic carbonatite.

5. Formula: Na2CO3
Mol Wt : 105.98g/mol
PHYSICAL PROPERTIES
It occurs as White greyish solid, hygroscopic
Odor: odorless
Taste: cooling salty taste (Alkali taste)
Density: 2.54g/cm3 at 25 C
Solubility: soluble in water, also in aq alcohol.
Melting Point: 34 °C (93 °F; 307 K)
(decahydrate)
851 °C (1,564 °F; 1,124 K)
decomposes (anhydrous)
PH: Alkaline

6.  Hydrolysis
 Na2CO3 when dissolved in water imparts a
highly alkaline reaction to the water as evident
by the fact of a molar solution is 6-11.
 Na2CO3 + 2H2O 2 NaOH + H2CO3

7.  Sodium carbonate in solution or in soled
form is capable of neutralizing acids with
the formation of salt, CO2 and Water.
 Na2CO3 + 2HCl 2NaCl + H2O + CO2
 Na2CO3 + H2SO4 Na2SO4 + H2O + CO2

8.  Sodium carbonate is used as reagent to precipitate
the insoluble carbonates of other metals like, silver
nitrate forms insoluble carbonate with sodium
carbonate.
 2AgNO3 + Na2CO3 Ag2CO3 + 2NaNo2

9.  Leblanc process
 In this process First, sea salt (sodium chloride) was boiled in sulfuric acid
to yield sodium sulfate and hydrogen chloride gas, according to the
chemical equation
2 NaCl + H2SO4 → Na2SO4 + 2 HCl
 Next, the sodium sulfate was blended with crushed limestone (calcium
carbonate) and coal, and the mixture was burnt, producing calcium
sulfide.
Na2SO4 + CaCO3 + 2 C → Na2CO3 + 2 CO2 + CaS
 The sodium carbonate was extracted from the ashes with water, and then
collected by allowing the water to evaporate.
 The hydrochloric acid produced by the Leblanc process was a major
source of air pollution, and the calcium sulfide byproduct also presented
waste disposal issues. However, it remained the major production method
for sodium carbonate until the late 1880s

10.  In 1861, the Belgian industrial chemist Ernest Solvay developed
a method to convert sodium chloride to sodium carbonate using
ammonia. The Solvay process centered around a large hollow
tower. At the bottom, calcium carbonate (limestone) was heated
to release carbon dioxide:
CaCO3 → CaO + CO2
 At the top, a concentrated solution of sodium chloride and
ammonia entered the tower. As the carbon dioxide bubbled up
through it, sodium bicarbonate precipitated:
NaCl + NH3 + CO2 + H2O → NaHCO3 + NH4Cl
 The sodium bicarbonate was then converted to sodium
carbonate by heating it, releasing water and carbon dioxide:
2 NaHCO3 → Na2CO3 + H2O + CO2

11.  Meanwhile, the ammonia was regenerated from the ammonium
chloride byproduct by treating it with the lime (calcium
hydroxide) left over from carbon dioxide generation:
CaO + H2O → Ca(OH)2
Ca(OH)2 + 2 NH4Cl → CaCl2 + 2 NH3 + 2 H2O
 Because the Solvay process recycles its ammonia, it consumes
only brine and limestone, and has calcium chloride as its only
waste product. This made it substantially more economical than
the Leblanc process, and it soon came to dominate world sodium
carbonate production.
 The Solvay process results in soda ash (predominantly sodium
carbonate (Na2CO3)) from brine (as a source of sodium chloride
(NaCl)) and from limestone (as a source of calcium carbonate
(CaCO3)). The overall process is:
2 NaCl + CaCO3 → Na2CO3 + CaCl2

12.  Sodium carbonate is used in medicine as an antacid.

Sodium carbonate is employed in the preparation of alkaline
baths for use in scaly, skin diseases and an aqueous solution
(0.5 per cent.) is used as a lotion, applied with a compress, to
relieve irritation in eczema.
 The carbonate is also used to prepare "bath salts," being
perfumed with oil of lavender for this purpose or in
effervescence with citric or tartaric acid.


13.  Balneum Alkalinum, B.P.C.—ALKALINE BATH. 1 in
1000. For a full sized bath dissolve 280 grams (5 ounces) of
sodium carbonate in crystals in 140 litres (30 gallons) of
water. This bath is used in skin diseases to remove scaly
incrustations, also in gout and rheumatism.
 Solution Sodii Carbonatis.—B.P. TEST SOLUTION OF
SODIUM CARBONATE. Sodium carbonate, 10g; distilled
water, sufficient to produce 100ml.

14.  Used topically for dermatides, mouthwash,
vaginal douche (Irrigation purpose)