C3- softening water

C3- softening water

1. Both types of water (temporary and hard) can be softened by adding washing soda (sodium carbonate)

   • The added carbonate ions react with CA,MG ions to make an insoluable precipitate of calcium carbonate and magnesium carbonate. The ions are no longer dissolved so cant make the water hard

2. Both types of hardness can also be removed by running water through ion exchange columns.

   • These are sold in shops and have lots of Na or H ions and exchange them for calcium or magnesium ions

3. Temporary hard water is removed by boiling

   • When heated, the calcium hydrogencarbonate decomposes to form calcium carbonate which is insoluable.
     • The solid is the limescale on your kettle.