Question

How is washing soda prepared from sodium carbonate? Give its chemical equation. State the type of this salt. Name the type of hardness of water which can be removed by it?

Answer 1

•  Washing soda is sodium carbonate containing 10 molecules of water of crystallisation. 

•  It is called as sodium carbonate decahydrate. It is prepared by Solvay's process. 

•  A cold and concentrated solution of sodium chloride is reacted with ammonia and carbon dioxide to obtain sodium hydrogen carbonate. 

• It can remove temporary and permanent hardness from water. Sodium carbonate is soluble but calcium carbonate and magnesium carbonate are insoluble. 

• The water is softened because it no longer contains dissolved calcium ions and magnesium ions. 

• It will form lather more easily with soap