Multiple choice general knowledge

How many waters of crystallisation are present in Alum?

  1. 12

  2. 16

  3. 20

  4. 24
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Common alum (potash alum) has the chemical formula K2SO4·Al2(SO4)3·24H2O, which contains 24 water molecules of crystallization. This double sulfate crystallizes with 24 water molecules in its hydrated form, making it a 24-hydrate compound.

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