The products formed when heavy water is reacted with magnesium nitride are:

When chlorine water is exposed to sunlight,$O_2$ is liberated. Hence

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

Find the number of $CORRECT$ order against mentioned property :-
$(i)$ $D_2O = H_2O$ (number of electrons)
$(ii)$ $D_2O > H_2O$ $(|\Delta H_f|)$
$(iii)$ $D_2O > H_2O$ $(|\Delta H_{vaporization}|)$
$(iv)$ $D_2O > H_2O$ (density)
$(v)$ $D_2O > H_2O$ (Molecular mass)

Is demineralised or distilled water useful for drinking purposes? If not,how can it be made useful?

Identify the statements which are not correct from the following:
a) In the structure of ice,each oxygen atom is surrounded by $4$ other hydrogen atoms via hydrogen bonding.
b) Temporary hardness of water is due to dissolved $Mg(HCO_3)_2$ and $Ca(HCO_3)_2$,not $NaHCO_3$.
c) In the reaction of acidified $KMnO_4$ and $H_2O_2$,$H_2O_2$ acts as a reducing agent.
d) $3 \ g \ L^{-1}$ $H_2O_2$ is not equal to $100$ volume $H_2O_2$ (since $100$ volume $H_2O_2$ is approximately $303.7 \ g \ L^{-1}$).