CAIE A Level Chemistry 9701 · The Periodic Table: chemical periodicity
Aluminium hydroxide, , is insoluble in water. When dilute hydrochloric acid is added to a suspension of aluminium hydroxide, the solid dissolves. When aqueous sodium hydroxide is added to a separate suspension of aluminium hydroxide, the solid also dissolves.
Suggest equations for the two reactions and use them to explain the acid/base behaviour of aluminium hydroxide.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Suggest means: Apply what you know to an unfamiliar situation. There may be more than one acceptable answer. Reason from the principle you have learned to the new context, and say which principle you are using.
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