Water softening by Clark's process uses

Statements about heavy water are given below.
$A.$ Heavy water is used in exchange reactions for the study of reaction mechanisms.
$B.$ Heavy water is prepared by exhaustive electrolysis of water.
$C.$ Heavy water has higher boiling point than ordinary water.
$D.$ Viscosity of $H_2O$ is greater than $D_2O$.

Boiling of hard water is helpful in removing the temporary hardness by converting calcium hydrogen carbonate and magnesium hydrogen carbonate to ....

The high density of water compared to ice is due to

$A$ sample of water contains $Mg(HCO_3)_2$ and $Ca(HCO_3)_2$. On boiling this water,these hydrogen carbonates are removed as precipitates. The precipitates are

When zeolite is treated with hard water,the sodium ions are exchanged with: