Chemistry - Hydrogen and Its compound Question with Solution | TestHub

Softening the temporary hardness of water means conversion of bicarbonate into calcium carbonate (precipitation) $$\begin{array}{c}\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2+\mathrm{Ca}(\mathrm{OH}{)}_2⟶\\ 2{\mathrm{CaCO}}_3\downarrow +2{\mathrm{H}}_2\mathrm{O}\\ \mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2+{\mathrm{Na}}_2{\mathrm{CO}}_3⟶\\ {\mathrm{CaCO}}_3\downarrow +2{\mathrm{NaHCO}}_3\end{array}$$ Even $\mathrm{NaOCl}$ can be used, as in aqueous medium $\overline{\mathrm{O}}\mathrm{Cl}$ gets hydrolysed and makes solution alkaline enough to cause precipitation of ${\mathrm{CaCO}}_3$. $$\begin{array}{rl}\mathrm{NaOCl}+{\mathrm{H}}_2\mathrm{O}& \rightleftharpoons \mathrm{HOCl}+\mathrm{NaOH}\\ {\mathrm{OH}}^{-}+{\mathrm{HCO}}_3^{-}& ⟶{\mathrm{CO}}_3^{2-}+{\mathrm{H}}_2\mathrm{O}\end{array}$$ Representative elements (Hydrogen and its compounds) Conceptual II