Sodium carbonate and sodium bicarbonate are very important chemical materials and used in many industries in the world.
Sodium carbonate is used to identify cations in qualitative analysis. It precipitates insoluble carbonates of calcium, barium and strontium.
When dilute acid(HCl, H2SO4) is added to a solid sodium carbonate(Na2CO3) , carbon dioxide gas is generated.
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.
Note : Alcohols and phenol do not react with sodium carbonate and sodium bicarbonate.
With hot milk of lime (Ca(OH)2), sodium carbonate react to form sodium hydroxide and calcium carbonate. Calcium carbonate exist as a precipitate.
All carbonates of alkali metals ( Group 1A) are stable to heat. Therefore decomposition of Na2CO3 is hard
Sodium bicarbonate( baking soda, sodium hydrogen carbonate) is obtained as an intermediate product in solvay process for the manufacturing of
Passing carbon dioxide to a cold concentrated solution of sodium carbonate will give sodium bicarbonate(NaHCO3).
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.
HCO3- of Ca2+ and Mg2+ cause to temporary hardness. Adding Na2CO3 will form CaCO3 and MgCO3 precipitates by removing HCO3-.
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.
Ammonia and sodium carbonate are given as products by the reaction of urea and NaOH.
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.
By the hydrolysis of carbonate ion, OH- ions are released.
Due to release of OH-, sodium carbonate solution is weak basic.
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.
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.
MNa2CO3 = 23*2 + 12 + 16*3
MNa2CO3 = 106 g mol-1
Solubility - 30.7 g/100 g water at 250C