Describe methods to remove the temporary hardness of water: $(i)$ Boiling $(ii)$ Clark's method.

(N/A) $(i)$ Boiling: During boiling,the soluble $Mg(HCO_{3})_{2}$ is converted into insoluble $Mg(OH)_{2}$ and $Ca(HCO_{3})_{2}$ is changed to insoluble $CaCO_{3}$. Because the solubility product of $Mg(OH)_{2}$ is lower than that of $MgCO_{3}$,$Mg(OH)_{2}$ precipitates out. These precipitates can be removed by filtration to obtain soft water.
$Mg(HCO_{3})_{2} \xrightarrow{\Delta} Mg(OH)_{2} \downarrow + 2CO_{2} \uparrow$
$Ca(HCO_{3})_{2} \xrightarrow{\Delta} CaCO_{3} \downarrow + H_{2}O + CO_{2} \uparrow$
$(ii)$ Clark's method: In this method,a calculated amount of lime $(Ca(OH)_{2})$ is added to hard water. It precipitates calcium carbonate and magnesium hydroxide,which can be filtered off.
$Ca(HCO_{3})_{2} + Ca(OH)_{2} \longrightarrow 2CaCO_{3} \downarrow + 2H_{2}O$
$Mg(HCO_{3})_{2} + 2Ca(OH)_{2} \longrightarrow 2CaCO_{3} \downarrow + Mg(OH)_{2} \downarrow + 2H_{2}O$