O-LevelChemistryBonding & Structure5070/11 · Oct/Nov 2025 · Q81 Mark

Aluminium ions, Al3+, react with sulfate ions, SO42-, to form aluminium sulfate. Which row shows the correct empirical formula and ionic formula of aluminium sulfate?

AAlSO4 Al3+SO42-

BAl2S2O8 Al3+(SO42-)2

CAl2S3O12 Al3+2(SO4)2-3

DAl3S2O8 Al2+3(SO4)2

✓ Correct answer

C: Al2S3O12 Al3+2(SO4)2-3

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Topic: Bonding & Structure, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, Oct/Nov 2025 Paper 1 Variant 1, question 8.

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