Sodium carbonate (English: sodium carbonate), commonly known as soda (soda), soda ash (soda ash, soda crystals), tetrahydrofurancarboxylic acid, and washing soda (washing soda). Chemical formula: Na2CO3, usually a white powder, is a strong electrolyte. The density is 2.532g/cm3, the melting point is 850°C, it is easily soluble in water and is alkaline. Has the properties of salt.
Preparation and application of sodium carbonate Preparation method
Pour sodium hydroxide into carbon dioxide to produce sodium carbonate. 2NaOH+CO2==Na2CO3+H2O
Preparation and application of sodium carbonate Hou’s alkali production method
Main article: Combined alkali production method
The reaction is carried out in three steps:
NH3+ CO2+ H2O → NH4HCO3
NH4HCO3+ NaCl → NaHCO3+ NH4Cl
2NaHCO3→ Na2CO3+ CO2+ H2O
During the reaction, since the solubility of sodium bicarbonate is significantly lower than that of ammonium bicarbonate and sodium chloride, it can crystallize out of water. The carbon dioxide (CO2) generated by the reaction can be recycled and reused, and ammonium chloride (NH4Cl) can react with quicklime to produce NH3, which can be reused as raw material:
2NH4Cl + CaO → 2NH3+ CaCl2+ H2O
The ammonia-alkali method enables continuous production, improves the utilization rate of salt, and the product quality is pure, so it is called “soda ash”, but the biggest advantage is its low cost.
Preparation and application of sodium carbonate, Solvay alkali production method
The difference between Hou’s (joint alkali production method) and Soxhlet’s method is that Treatment of ammonium bicarbonate. Soxhlet added quicklime to cause ammonia to escape, while Hou’s added salt to crystallize ammonium chloride.
Preparation and application of sodium carbonate
The main industrial application areas of sodium carbonate are flat glass, daily glass, synthetic laundry detergent, neutralization Acid waste, alumina and other industries.
In production and life, sodium carbonate is used to make pasta, prepare sodium hydroxide, etc., or as a formula for various detergents. Use it as a softener for water purification.
Sodium carbonate will decompose to a small amount at extremely high temperatures (above 1000°C), but without the addition of the additive sodium tetraborate, even at 1270°C, it will still only partially decompose within a few hours. (<2%).
Before the 19th century, the preparation of sodium hydroxide usually used the Leblanc process to generate the precursor sodium carbonate, and then calcined it at high temperature to differentiate the sodium carbonate into sodium oxide and carbon dioxide. Finally, Sodium hydroxide can be obtained by dissolving sodium oxide in water:
Na2CO3→ Na2O + CO2
Na2O+H2O→2NaOH
This reaction is The principle of producing sodium hydroxide by the Brownian process.
