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O-LevelChemistryAcids, Bases & Salts5070/11 · Oct/Nov 2025 · Q401 Mark

A colourless solution of compound W is tested separately with a few drops of aqueous sodium hydroxide and a few drops of aqueous ammonia. No precipitate is observed in either of the tests. What is the cation in W?

AAl3+

BCa2+

CCu2+

DNH4+

✓ Correct answer

D: NH4+

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About this question

Topic: Acids, Bases & Salts, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, Oct/Nov 2025 Paper 1 Variant 1, question 40.

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