$A$ sample of water contains sodium chloride. It is:

Some statements about heavy water are given below:
$(i)$ Heavy water is used as a moderator in nuclear reactors.
$(ii)$ Heavy water is more associated than ordinary water.
$(iii)$ Heavy water is more effective solvent than ordinary water.
Which of the above statements are correct?

Which process is used for the removal of hardness of water?

The temporary hardness of water is due to

When temporary hard water containing $Mg(HCO_3)_2$ is boiled,the precipitate formed is of:

The reagent$(s)$ used for softening the temporary hardness of water is(are):
$(A)$ $Ca_3(PO_4)_2$
$(B)$ $Ca(OH)_2$
$(C)$ $Na_2CO_3$
$(D)$ $NaOCl$