An aqueous solution of copper(II) sulfate is treated with concentrated hydrochloric acid until there is no further change. Which statement correctly describes the changes in the copper complex and the observations made?
The coordination number of the copper complex changes from 6 to 4, and a yellow precipitate forms with the evolution of a gas.
The coordination number of the copper complex changes from 6 to 4, the solution changes from pale blue to yellow-green, and no precipitate forms.
The coordination number of the copper complex remains 6, the solution changes from pale blue to yellow-green, and no precipitate forms.
The coordination number of the copper complex changes from 6 to 2, the solution becomes colourless, 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.