What is observed when concentrated hydrochloric acid is added to an aqueous solution of cobalt(II) sulfate, CoSO4\text{CoSO}_4CoSO4, until no further change occurs?
A colourless gas is evolved and a precipitate forms.
A colourless gas is evolved and no precipitate forms.
A precipitate forms that dissolves in an excess of concentrated hydrochloric acid.
The solution changes colour and no precipitate forms.
63 exam-style questions on AQA A Level Chemistry Transition metals (A-level only), covering General properties of transition metals (A-level only), Substitution reactions (A-level only), Shapes of complex ions (A-level only), Formation of coloured ions (A-level only), Variable oxidation states (A-level only), and Catalysts (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.