A-LevelChemistryEquilibria9701/12 · Oct/Nov 2019 · Q111 Mark

Hydrated aluminium ions undergo the following reaction. [Al(H₂O)₆]³⁺(aq) + H₂O(l) ⇌ [Al(H₂O)₅OH]²⁺(aq) + H₃O⁺(aq) Which statement about this reaction is correct?

AH₂O(l) and [Al(H₂O)₅OH]²⁺(aq) are a conjugate acid-base pair.

BH₂O(l) is acting as an acid as it is donating H⁺ ions.

CIf OH⁻(aq) is added, the equilibrium will move to the right.

DK varies as the pH is varied.

✓ Correct answer

C: If OH⁻(aq) is added, the equilibrium will move to the right.

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Topic: Equilibria, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source: A-Level Chemistry, Oct/Nov 2019 Paper 1 Variant 2, question 11.

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