Edexcel Jan 2013 Paper 5 Q14

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SECTION B Answer ALL the questions. Write your answers in the spaces provided. 14 This question concerns the chemistry of copper. In the sequence below, A, B, C, D, E and F all contain copper in various oxidation states. CuSO4(aq) NaOH A (pale blue solid) heat B (black solid) KI(aq) NH3(aq) copper(I) iodide C (dark blue solution) H2SO4(aq) NH3(aq) vigorous shaking D (pink solid) + E (blue solution) F (colourless solution) (a) Identify, by name (including the oxidation state where appropriate) or formula, the copper-containing species in the sequence. (6) ABCDEF10 *P41215A01024*<br /> (b) Identify, by name or formula, the reagent that would be used to convert B into CuSO4(aq). (1)(c) (i) C and F are the same type of chemical species. Name this type. (1)(ii) Explain why C is coloured but F is colourless. (3)*(iii) Explain why F changes into C on shaking. (2)*P41215A01124* 11 Turn over<br /> (d) The reaction of copper(I) iodide to form D and E is a disproportionation. (i) Explain the term disproportionation. (2)(ii) Write an ionic equation for this reaction. State symbols are not required. (iii) Use the relevant standard reduction (electrode) potentials, from the table on page 17 of your data booklet, to calculate the E 9 giving your answer with the appropriate sign. cell value for this reaction, (1) (2) 12 *P41215A01224*<br /> *(iv) If copper(I) iodide is treated with nitric acid, rather than sulfuric acid, a blue solution is still formed but no pink solid. Use the standard electrode potentials on page 15 of your data booklet to explain this. Quote any data that you use. (4)(Total for Question 14 = 22 marks) *P41215A01324* 13 Turn over<br />

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