AQA Jun 2012 Paper 5 Q8

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do not write outside the box a this question is about cobalt chemistry consider the following reaction scheme that starts from co h o ions w x and y are ions and z is a compound reaction pink purple precipitate co h o reaction reaction pale yellow solution dark brown solution reaction blue solution for each of the reactions to identify a suitable reagent identify w x y and z and write an equation for each of reactions to marks extra space question continues on the next page turn over wmp jun chem do not write outside the box b a flue gas desulfurisation process involves the oxidation by oxygen of aqueous sulfate iv ions so catalysed by co ions in an acidic aqueous solution into aqueous sulfate vi ions so this reaction is write an equation for the overall reaction of sulfate iv ions with oxygen to form sulfate vi ions suggest why this overall reaction is faster in the presence of co ions suggest a mechanism for the catalysed reaction by writing two equations involving co and co ions you will need to use h ions and h o to balance these two equations marks end of questions copyright aqa and its licensors all rights reserved wmp jun chem

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