ChemistryWaterJAMB
Permanent hardness of water can be removed by
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Answer: B. adding washing soda
Na₂CO₃ precipitates the Ca²⁺ and Mg²⁺ ions as insoluble trioxocarbonates(IV); boiling removes only temporary hardness.
An AdmitMe practice question, written for the JAMB syllabus. Not an official past question.