Heavy water $(D_2O)$ is used as:

When zeolite,which is a hydrated sodium aluminium silicate,is treated with hard water,the sodium ions are exchanged with which of the following?

Select the correct statement about water.
$(i)$ Critical temperature of $H_2O$ is less than $NH_3$.
$(ii)$ Standard boiling point of water is $100 \ ^oC$.
$(iii)$ Critical volume of $H_2O$ is less than $NH_3$.

Describe the physical properties of water.

Which of the following methods is the best test to detect the presence of water in a liquid?

$A$ 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