The temperatures of maximum density in $H_2O$ and $D_2O$ respectively are:

The boiling point of heavy water is ............ $^o C$?

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

Assertion $(A)$ : $NaCl$ is less soluble in heavy water than in ordinary water.
Reason $(R)$ : Dielectric constant of ordinary water is more than that of heavy water.
The correct answer is

Water is often treated with chlorine,because it

Permanent hardness of water can be removed by