Rajasthan BoardEnglish MediumSTD 12 ScienceChemistrySurface Chemistry1 Mark
Question
Why do we add alum to purify water?
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Answer
We add alum to purify water as alum coagulates the colloidal impurities present in water, so that these impurities get settle down and remove by decantation or filtration. Thus, water gets purified by adding alum to water.
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