Hardness of water is mainly due to the presence of
- calcium hydroxide or magnesium hydroxide
-
calcium trioxocarbonate (IV) or calcium tetraoxosulphate (VI)
- sodium hydroxide or magnesium hydroxide
- calcium chloride or sodium chloride salts
The correct answer is: B
Explanation
Salts of Calcium and Magnesium are responsible for hardness of water. Bicarbonates, Carbonates, Chlorides and Sulfates of Calcium and Magnesium causes temporary and permanent hardness.
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