soda ash is formed by the reaction of carbonic acid and sodium hydroxide .write this reaction and give two uses of soda ash
Answers
Explanation:
Sodium carbonate is an inorganic chemical compound. Sodium carbonate is what is commonly known as Soda ash. Soda ash is extracted from trona. Trona is a double salt containing sodium carbonate and sodium hydrogen carbonate formed as a result of the series of evaporation processes taking place at lakes.
Sodium carbonate often called washing soda or soda ash is the most important of all basic heavy chemicals. Its great advantage over sodium hydroxide is that it is no-corrosive and is, therefore, safer to handle.
Sodium Carbonate Formula
Sodium carbonate is a diazonium salt of carbonic acid with chemical formula Na2CO3. It is also known as Soda crystals, soda ash, washing soda. This inorganic compound is water-soluble and when dissolved in water, it forms carbonic acid and sodium hydroxide. In its pure form, it is white powder and odourless. It is a strong base and acts as an antacid.
Sodium carbonate can be produced by four processes – “Solvay process, Labnac process, Dual-process, Electrolytic process”. Since it is a weak acid it is slightly soluble in ethanol and insoluble in alcohol. One of the important uses of Na2CO3 is as a water softener. pH is about 11.
Synthesis of Sodium Carbonate – Na2CO3
Sodium carbonate is now exclusively manufactured by the Solvey process. In this process carbon dioxide and ammonia are passed into a cold saturated solution of sodium chloride. In the reactions which occur sodium hydrogen carbonate is formed which is only very slightly soluble in the presence of sodium ions, is almost completely precipitated. It is removed by filtration and ignited to produce sodium carbonate.
The ingredients of this process are readily available and inexpensive. These are salt brine (NaCl), ammonia (NH3) and limestone (CaCO3). In this process, CaCl2 is an important by-product obtained.
The reactions can be represented by the following equation.
2NH3 + H2O + CO2 → (NH4)2CO3
(NH4)2CO3 + H2O + CO2 → 2NH4HCO3
Addition of common salt to the solution containing NH4+ and HCO3– results in the precipitation of NaHCO3 which is least soluble. It is then filtered off.
NH4HCO3 + NaCl → NH4Cl + NaHCO3
Sodium bicarbonate is then heated to give Na2CO3.
2NaHCO3 → Na2CO3 + CO2 + H2O
The CO2 gas evolved can be reused again.
Anhydrous sodium carbonate is dissolved in water and recrystallizes to get washing soda crystals containing 10 molecules of water of crystallization.