Hard water contains dissolved salts such as magnesium and calcium chlorides, bicarbonates, or sulphates. There are two kinds of hardness of water, i.e. temporary hardness and permanent hardness.
Permanent hardness of water can be removed by

Options

A. distillation
B. passing it through ion-exchange resins
C. adding various phosphates.
D. adding `Na_2 CO_3` solution.

Answer

A, B, C, D