Question

Temporary hardness may be removed from water by adding.

• A. $CaCO_{3}$
• B. $Ca(OH)_{2}$
• C. $CaSO_{4}$
• D. HCl

Answer 1

Answer: (B)

$Ca(OH)_{2}$

Answer 2

$Ca(HCO_{3})_{2} + Ca(OH)_{2} \rightarrow \underset{\text{ppt.}}{2CaCO_{3} \downarrow} + 4H_{2}O$