Question

what is the reaction between the soap molecules and ions present in hard water

Answer 1

soap has molecules of sodium and potassium which reacts with magnesium and calcium to form an insoluble precipitate called scum ..... which do not allow to clothes to be washed properly ....

Answer 2

Hey dear,

● Reaction of soap with hard water -
- Hard water contains salts of calcium and magnesium principally as bicarbonates, chlorides, and sulfates.
- These ions displace sodium ion from soap molecules to form insoluble ppt (scum).

Ca2+ + 2Na(stearate)↓ → Ca(stearate)2 + 2Na+
Mg2+ + 2Na(stearate)↓ → Mg(stearate)2 + 2Na+

Hope this helps you.
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