HARDNESS OF WATER

Hardness:

               A water with on treatment with soap doesnot produce leather is called hardwater. Mainly hardness of water is due to salts of  Ca and Mg and other heavy metals dissolved in water.

                                  



Types of hardness:

1.  temporary hardness
2. permanent hardness

1.Temporary hardness: 

                                  It is caused by soluble bicarbonates of Ca and Mg. It is removed by boiling of water.

2.Permanent hardness:

                                 It is caused by presence of chlorides and sulphates of Ca and Mg,iron and heavy metals.It is also called noncarbonate hardness. 

Softening of water:  

                                       Process of removing hardness of water is called softening of water.

Chemicals required for removing hardness of water:

                                Ca(OH)₂ ,  Na₂CO₃