How to remove temporaray and permanent water hard ?
The presence of magnesium and calcium carbonates in water makes it temporarily hard. In this case the hardness in water can be removed by boiling the water. When we boil water the soluble salts of Mg(HCO3)2 is converted to Mg(OH)2 which is insoluble and hence gets precipitated and is removed.
Sodium carbonate, Na 2CO 3, is also known as washing soda. It can soften water that has temporary hardness and it can soften water that has permanent hardness. The calcium ions come from the hard water and the carbonate ions from the washing soda.