When temporary hard water containing $$ Mg(HCO_{3})_{2} $$ is boiled, the ppt. formed is of
Correct option is C. $$ Mg(OH)_2$$
$$ Mg(OH)_{2} $$ is less soluble than $$ MgCO_{3} $$. On boiling temporary hard water containing $$ Mg^{2+} $$ ions, the ppt. obtained is of $$ Mg(OH)_{2} $$ and not that of $$ MgCO_{3} $$.
$$MgCO_3+H_2O\xrightarrow{\Delta} Mg(OH)_2\downarrow+CO_2$$