What is the ratio of the number of molecules of water of crystallization to the total number of metal ions in one formula unit of potash alum?

Step-by-step solution

The chemical formula of potash alum is K ₂ SO ₄ Al ₂( SO ₄)₃ 24 H ₂ O . The number of molecules of water of crystallization in one formula unit is 24 . The metal ions present in the formula are K ^+ and Al ³⁺ . Number of K ^+ ions = 2 Number of Al ³⁺ ions = 2 Total number of metal ions = 2 + 2 = 4 . The ratio of the number of water molecules to the total number of metal ions is 24:4 , which simplifies to 6:1 . A ratio of 12:1 would incorrectly result from counting only one type of metal ion, while 3:1 would result