Sodium carbonate, characteristics, properties and production, and chemical reactions.
Sodium carbonate is an inorganic substance and has chemical formula Na2CO3.
Sodium carbonate (soda ash) is an inorganic substance of white color.
The chemical formula of calcium carbonate Na2CO3.
Sodium carbonate (soda ash) – inorganic compound, the sodium salt of carbonic acid.
Sodium carbonate should not be confused with sodium bicarbonate (baking soda) NaHCO3 and sodium hydroxide (caustic soda) NaOH.
Sodium carbonate is a colorless crystals, under normal conditions, is a white powder, which melt at a temperature of 854 °C without decomposition, and decompose upon further heating at a temperature higher than 1000 °C.
Sodium carbonate has three versions:
– α-modification. It has a monoclinic crystal lattice, is formed at a temperature up to 350 °C;
β – modification. Formed when heated above 350 °C to 479 °C. Also has a monoclinic crystal lattice;
– γ-modification. Formed when heated in excess of 479 °C. Has a hexagonal crystal lattice.
Dissolves well in water, creating a strongly alkaline medium and in glycerol. Slightly soluble in ethanol. Not soluble in acetone and carbon disulphide.
In nature, sodium carbonate is found in the form of minerals:
of nahcolite having the chemical formula NaHCO3. Nahcolite is a mineral of the subclass of carbonates, the crystalline form of sodium bicarbonate. The name is formed from the first letters of the chemical symbols of the elements included in its composition: Na, H, C and O;
– throne, having chemical formula Na2CO3·NaHCO3·2H2O. The name tron comes from the Arabic names of natural salt. Another name for the throne – Egyptian salt;
of nitrite, having chemical formula Na2CO3·10H2O. Nutrit is the decahydrate of sodium carbonate. The other name of nutrica – natron, soda and crystal soda;
of thermonatrite, having chemical formula Na2CO3·H2O. Thermonatrite – monohydrate of sodium carbonate. Is formed by dehydration of the decahydrate of sodium carbonate Na2CO3·10H2O. The other name of thermonatrite – soda.
Sodium carbonate is also found in the ash of certain marine algae.
|Synonyms and foreign language names||sodium carbonate (eng.)
sodium carbonate (Rus.)
soda ash (eng.)
|The type of substance.||inorganic|
|Appearance||colorless monoclinic crystals|
|Aggregate state (at 20 °C and atmospheric pressure of 1 ATM.)||solid|
|Density (state of matter – solid, at 20 °C) g/cm3||Of 2.53|
|Decomposition temperature, °C||1000|
|Melting point, °C||854|
|Water solubility at 20 0C g/100 ml||21,8|
|The dissociation constant of the acid, pKa||Of 10.33|
|Molar mass, g/mol||105,99|
— no data.
In industry, sodium carbonate is obtained in several ways:
1. way Solvay (ammonia method):
NaCl + H2O + NH3 + CO2 → NaHCO3 + NH4Cl;
NaHCO3 → Na2CO3 + CO2 + H2O (t = 140-160 °C).
Using a saturated solution of sodium chloride is passed a mixture of gasesconsisting of ammonia and carbon monoxide, the result is a slightly soluble sodium bicarbonate (9.6 g per 100 g water at 20 °C), which is then filtered and calcine (dehydrate) by heating to 140-160 °C. results In the formation of sodium carbonate.
The resulting CO2 is returned to the production cycle.
Ammonium chloride NH4Cl is treated with calcium hydroxide Ca(OH)2:
NH4Cl + CA(Oh)2 → СаCl2 + 2NH3 + 2H2O.
The obtained NH3 also return to the production cycle.
Thus, the only waste product is calcium chloride.
2. way Howe.
NaCl + H2O + NH3 + CO2 → NaHCO3 + NH4Cl;
NaHCO3 → Na2CO3 + CO2 + H2O (t = 140-160 °C).
The way HOU is different from the Solvay process that is not used calcium hydroxide.
According to the method of HOU in a solution of sodium chloride at a temperature of 40 °C is fed carbon dioxide and ammonia. The less soluble sodium bicarbonate during the reaction precipitates (as in the Solvay method). The solution was then cooled to 10 °C. thus precipitated ammonium chloride, and the solution is used repeatedly for production of the following portions of soda. This method differs from the Solvay process that uses calcium hydroxide.
The resulting ammonium chloride NH4Cl used in the future as a standalone product as fertilizer.
In the laboratory the sodium carbonate will receive:
3. as a result of reaction of calcium carbonate with sodium sulfide:
Na2S + CaCO3 → Na2CO3 + CaS (t = 1200 oC).
Sodium carbonate is the average salt formed by a weak acid – carbonic (H2CO3) and strong base – sodium hydroxide (NaOH).
Na2CO3 aqueous solutions are alkaline reaction.
For sodium carbonate characterized by the following chemical reaction:
1. the reaction of sodium carbonate and carbon:
Na2CO3 + 2C → 2Na + 3CO (t = 900-1000 oC).
In the reaction, the formed carbon monoxide and sodium.
2. the reaction of sodium carbonate and bromine:
3Br2 + 3Na2CO3 → 5NaBr + NaBrO3 + 3CO2.
In the reaction, the formed sodium bromide, sodium bromate and carbon dioxide. During the reaction the sodium carbonate used in the form of a concentrated hot solution.
3. the reaction of sodium carbonate and iodine:
3Na2CO3 + 3H2 → 5NaI + NaIO3 + 3CO2.
The reaction formed sodium iodide and the Iodate of sodium and carbon dioxide. During the reaction the sodium carbonate used in the form of a concentrated hot solution.
4. the reaction of sodium carbonate and chlorine:
3Na2CO3 + 3Cl2 → 5NaCl + NaClO3 + 3CO2.
The reaction produces sodium chloride, sodium chlorate and carbon dioxide. During the reaction the sodium carbonate used in the form of a concentrated hot solution.
5. the reaction of sodium carbonate and nitric acid:
Na2CO3 + 2HNO3 → 2NaNO3 + CO2 + H2O.
The reaction produces sodium nitrate, carbon dioxide and water. In the course of the reaction nitric acid is used in dilute solution.
6. the reaction of sodium carbonate and carbonic acid:
H2CO3 + Na2CO3 → 2NaHCO3.
The reaction produced sodium bicarbonate.
7. the reaction of sodium carbonate and orthophosphoric acid:
Na2CO3 + H3PO4 → Na2HPO4 + H2O + CO2
Na2CO3 + 2H3PO4 → 2NaH2PO4 + H2O + CO2
3Na2CO3 + 2H3PO4 → 2Na3PO4 + 3H2O + 3CO2 (to).
The reaction in the first case are formed gidrogenfosfat sodium, carbon dioxide and water, in the second case – digidrogenfosfat sodium, carbon dioxide and water, in the third case, the orthophosphate of sodium, carbon dioxide and water. In the course of the reaction in the first and third case, phosphoric acid is used in dilute solution in the second – in the form of a concentrated solution. The sodium carbonate in the first and second reactions used in the form of dilute solution, in a third – in the form of a concentrated solution. The third reaction proceeds while boiling.
Similar reactions occur with other acids.
8. the reaction of sodium carbonate and hydrogen fluoride:
Na2CO3 + 2HF → 2NaF + CO2 + H2O.
9. the reaction of sodium carbonate and silicon oxide:
Na2CO3 + SiO2 → Na2SiO3 + CO2 (t = 1150 OC).
The reaction form carbon dioxide and metasilicate sodium.
10. the reaction of sodium carbonate and sulfur dioxide:
SO2 + Na2CO3 → Na2SO3 + CO2,
2SO2 + Na2CO3 → Na2S2O5 + CO2 (t = 40-60oC).
In the first case, the reaction form carbon dioxide and sulphate of sodium. In the reaction, sodium carbonate is used in the form of a concentrated solution. The reaction proceeds at room temperature.
In the first case, the reaction form carbon dioxide and sodium disulfite. In the reaction, sodium carbonate is used in the form of a concentrated solution. The reaction proceeds at a temperature of 40-60oC.
11. the reaction of sodium carbonate and aluminium oxide:
Al2O3 + Na2CO3 → 2NaAlO2 + CO2 (t = 1000-1200 oC).
The reaction form carbon dioxide and aluminate of sodium.
12. the reaction of sodium carbonate and iron oxide:
Fe2O3 + Na2CO3 → 2NaFeO2 + CO2 (t = 800-900 oC).
In the reaction, the formed carbon dioxide and sodium ferrite.
13. the reaction of sodium carbonate and water (hydrolysis of sodium carbonate):
Na2CO3 + H2O ⇄ NaHCO3 + NaOH.
The reaction produces sodium bicarbonate and sodium hydroxide. The reaction is reversible.
14. the reaction of sodium carbonate, calcium oxide and water:
Na2CO3 + CaO + H2O → CaCO3 + 2NaOH.
The reaction produces calcium carbonate and sodium hydroxide.
15. the reaction of sodium carbonate, carbon dioxide and water:
Na2CO3 + CO2 + H2O → 2NaHCO3.
The reaction produced sodium bicarbonate. This reaction is a method of producing bicarbonate by passing carbon dioxide through a cold solution of sodium carbonate.
16. the reaction of sodium carbonate and calcium hydroxide (caustification of soda):
Na2CO3 + Ca(OH)2 → CaCO3 + 2NaOH.
The reaction formed a calcium carbonate and sodium hydroxide. This reaction provides a method of producing sodium hydroxide. The reaction equilibrium is shifted toward the formation of NaOH due to the poor solubility of CaCO3.
17. the reaction of thermal decomposition of sodium carbonate:
Na2CO3 → Na2O + CO2 (t = 1000 oC).
In the reaction, the formed carbon dioxide and sodium oxide.
Sodium carbonate is used in many industries and for domestic purposes:
in glass production;
– household chemicals: washing and cleaning powders;
– soap making;
– in manufacture of enamels to obtain the ultramarine;
– water softeners steam boilers;
for reducing hardness of water;
– for degreasing of metals and desulfurization pig iron;
– in the food industry as food additive E500 – regulator of acidity, baking powder, prevent clumping and caking;
– in the oil industry in combination with surfactants to reduce interfacial tension between water and oil;
– in the chemical industry as starting material for obtaining NaOH, Na2B4O7, Na2HPO4;
– in the tobacco industry (cigarette filters);
– the picture is a part of the developers as the accelerating means;
– in motor oil to prevent polymerization (concentration 2 g per 1 liter of oil).
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