Question: The temporary hardness of water is due to:
$\mathrm{Na}_{2} \mathrm{SO}_{4}$
$\mathrm{NaCl}$
$\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}$
$\mathrm{CaCl}_{2}$
Correct Option: , 3
Solution:
Unly bicarbonates cause temporary hardness, whereas chlorides and sulphates cause permanent hardness.
