- The hard water from a well or a bore-well becomes soft on adding washing soda and we come to know this from the lather formed on it.
- The hardness of water is due to the presence of chlorides and sulphates of calcium and magnesium in it.
- Na2CO3 is added to it to soften such water and make it suitable for use.
- The reaction with Na2CO3 causes the formation of insoluble carbonate salts of magnesium and calcium.
- Chemical reaction
Magnesium Sodium Magnesium Sodium chloride carbonate carbonate chloride