Sodium carbonate and bicarbonate reactions | Na2CO3 | NaHCO3

Sodium carbonate and sodium bicarbonate are very important chemical materials and used in many industries in the world.

Washing soda, soda ash, baking soda

  • Sodium carbonate (Washing soda, soda ash) - Na2CO3
  • Sodium bicarbonate (baking soda) - NaHCO3


Sodium carbonate in qualitative analysis

Sodium carbonate is used to identify cations in qualitative analysis. It precipitates insoluble carbonates of calcium, barium and strontium.



Sodium carbonate and acid reaction

When dilute acid(HCl, H2SO4) is added to a solid sodium carbonate(Na2CO3) , carbon dioxide gas is generated.

Sodium bicarbonate and acid reaction


Sodium carbonate and carboxylic acid reaction

Sodium carbonate and carboxylic acids (RCOOH) react to give CO2 and RCOO-Na+ and water. Also sodium bicarbonate reacts with carboxylic acid to give CO2.

Sodium carbonate and carboxylic acid reaction

Note : Alcohols and phenol do not react with sodium carbonate and sodium bicarbonate.


Sodium carbonate and milk of lime reaction

With hot milk of lime (Ca(OH)2), sodium carbonate react to form sodium hydroxide and calcium carbonate. Calcium carbonate exist as a precipitate.

Sodium carbonate and milk of lime reaction - Na2CO3 + Ca(OH)2

Decomposition of Na2CO3

All carbonates of alkali metals ( Group 1A) are stable to heat. Therefore decomposition of Na2CO3 is hard


Sodium bicarbonate or baking soda, NaHCO3

Sodium bicarbonate( baking soda, sodium hydrogen carbonate) is obtained as an intermediate product in solvay process for the manufacturing of sodium carbonate.

Preparing sodium bicarbonate in the laboratory

Passing carbon dioxide to a cold concentrated solution of sodium carbonate will give sodium bicarbonate(NaHCO3).

Preparing sodium bicarbonate in the laboratory

Properties of sodium bicarbonate

  1. Sparingly soluble in water
  2. A white crystalline solid
  3. When heating(373K), it decomposes into sodium carbonate, carbon dioxide and water. sodium bicarbonate decomposition
  4. Aqueous solution of sodium bicarbonate is alkaline in nature. aqueous sodium bicarbonate


How sodium carbonate is used to remove hardness of water?

There are two types of hardness of water as temporary hardness and permanent hardness. Na2CO3 can be used to remove both temporary hardness and permanent hardness.


Remove temporary hardness of hard water

HCO3- of Ca2+ and Mg2+ cause to temporary hardness. Adding Na2CO3 will form CaCO3 and MgCO3 precipitates by removing HCO3-.

Remove temporary hardness of hard water

Remove permanent hardness of hard water

SO42- and Cl- of Ca2+ and Mg2+ cause to permanent hardness. Adding Na2CO3 will form CaCO3 and MgCO3 precipitates by removing Ca2+ and Mg2+ from water.

Remove permanent hardness of hard water


Reactions of sodium carbonate preparing


Urea and NaOH reaction

Ammonia and sodium carbonate are given as products by the reaction of urea and NaOH.

Urea and NaOH reaction

Questions and answers of Na2CO3 and solvay process


Is sodium carbonate acidic or basic?

sodium carbonate is a basic compound. sodium carbonate dissociates completely in the water to Na+ ion CO32- ion. Na+ ion is stable in the water. But CO32- is not stable in the water and is hydrolyzed in the water.

carbonate ion hydrolysis

By the hydrolysis of carbonate ion, OH- ions are released.

carbonate ion hydrolysis reactions

Due to release of OH-, sodium carbonate solution is weak basic.



What is soda ash?

Sodium carbonate is a white crystalline solid which exists as a decahydrate (Na2CO3.10H2O). This is called washing soda. When decahydrate gets heat, it looses the water of crystallization to form monohydrate ( Na2CO3.H2O). Above 373K, the monohydrate becomes completely anhydrous and changes to a white powder called soda ash.


What will happen when calcium chloride aqueous solution is added to sodium carbonate solution?

With addition of calcium chloride (CaCl2), there are Na+, CO32-, Ca2+ and Cl- ions in the water. We know CaCO3 is a precipitate. Therefore in higher concentrations of Ca2+ and CO32- ions in aqueous solution, a white precipitate (CaCO3) is formed.

sodium carbonate and calcium chloride

Molecular mass of sodium carbonate

MNa2CO3 = 23*2 + 12 + 16*3

MNa2CO3 = 106 g mol-1



What is the solubility of sodium carbonate ?

Solubility - 30.7 g/100 g water at 250C






Chemical Industries in the World

Cement Production Ammonia Manufacturing Process - Haber Process Urea Production and Manufacturing Process Nitric Acid Production and Manufacturing Process Calcium Carbide & Acetylene gas Production Bleaching powder uses and Production Sulfuric Acid Production Process - Contact Process Rubber Products and Manufacturing Process Sodium Carbonate Manufacturing Process - Solvay Process