Question

How is washing soda obtained from sodium chloride? Give the chemical equations of the reactions involved in the process.

Hint:

Washing soda is obtained from sodium chloride through the Solvay process, involving sodium bicarbonate precipitation, heating, and crystallization.

Answer 1

Washing soda (\({Na}_2{CO}_3 \cdot 10{H}_2{O}\)) is obtained from sodium chloride (\({NaCl}\)) through the Solvay process. The process involves the following steps: 
Formation of Sodium Bicarbonate: In the Solvay process, sodium chloride (\({NaCl}\)) reacts with ammonia (\({NH}_3\)) and carbon dioxide (\({CO}_2\)) in water to form sodium bicarbonate (\({NaHCO}_3\)), which precipitates out. \[ {NaCl} + {NH}_3 + {CO}_2 + {H}_2O \rightarrow {NaHCO}_3 + {NH}_4Cl \] Conversion of Sodium Bicarbonate to Sodium Carbonate: Sodium bicarbonate is heated to form sodium carbonate (\({Na}_2{CO}_3\)). \[ 2{NaHCO}_3 \xrightarrow{{heat}} {Na}_2{CO}_3 + {CO}_2 + {H}_2O \] Formation of Washing Soda: Sodium carbonate (\({Na}_2{CO}_3\)) is dissolved in water and recrystallized to obtain washing soda (\({Na}_2{CO}_3 \cdot 10{H}_2{O}\)). \[ {Na}_2{CO}_3 + 10{H}_2{O} \rightarrow {Na}_2{CO}_3 \cdot 10{H}_2{O} \] The final product, washing soda, is used in cleaning and water softening.