The one that is $NOT$ suitable for the removal of permanent hardness of water is :

Which of the following is the best scientific method to test the presence of water in a liquid?

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)

Zeolite is hydrated sodium aluminium silicate. When treated with hard water,the sodium ions in zeolite are exchanged with

Temporary hardness and permanent hardness can be removed by the sequential addition of which of the following?

Which physical constant for $H_2O$ has a higher magnitude than $D_2O$?