Question

Temporary hardness of water can be removed by adding:

• A. $NaOH$
• B. $N{a}_{2}C{O}_3$
• C. $Ca(OH{)}_2$
• D. $MgC{l}_2$

Answer 1

Answer: (C)

$Ca(OH{)}_2$

Temporary hardness of water can be removed using Clark's method by adding $Ca(OH{)}_2$. In Clark's process, slaked lime $Ca(OH{)}_2$ is added to temporary hard water. Insoluble calcium carbonate precipitates out and thus, temporary hardness is removed.