Which of the following can effectively remove all types of hardness of water ?

Options

A. Washing soda
B. Soap
C. Slaked lime
D. Boiling.

Answer

B

Explanation

Washing sode can effectively remove hardness due to `Ca^(2+)` ions, but cannot remove the hardness due to `Mg^(2+)` ions as `MgCO_(3)` is quite soluble in water. Slaked lime can remove temporary hardness, but permanent hardness due to `Mg^(2+)` when removed with `Ca(OH)_(2)` introduces `Ca^(2+)` ions in solution, thus making it hard once again. Boiling can remove only temporary hardness. Soap can effectively remove all types of hardness.