Question

How the process of boiling soften water?

Answer 1

(1)Water is said to be soft,if it readily forms lather with soap.

(2)Water is said to be hard when it does not readily form lather with soap.

Removal of temporary hardness by boiling:-

By boiling,carbon dioxide is driven off and the soluble hydrogen carbonates are converted into insoluble carbonates and could be removed by filtration or decantation.

$\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2\left(\mathrm{aq}\right)\to {\mathrm{CaCO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$

Calcium carbonate and magnesium carbonate are precipitated leaving the water soft.

Therefore,this is how temporary hardness can be removed by boiling.