Question

Why presence of calcium bicarbonate in water give rise to temporary hardness in water but presence of sodium bicarbonate does not.
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Answer 1

Temporary hardness is due to thepresence of calcium hydrogencarbonate Ca(HCO3)2(aq) and magnesium hydrogencarbonate Mg(HCO3)2(aq). ... This removes the calcium ions or magnesium ions from the water, and so removes the hardness. Therefore,hardness due to hydrogencarbonates issaid to be temporary.

Answer 2

Explanation:

Temporary hardness is due to the presence of calcium hydrogencarbonate Ca(HCO3)2(aq) and magnesium hydrogencarbonate Mg(HCO3)2(aq). ... This removes the calcium ions or magnesium ions from the water, and so removes the hardness. Therefore, hardness due to hydrogencarbonates is said to be temporary.