AQA Jan 2012 Paper 2 Q4

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do not write outside the box a iron is extracted from iron iii oxide using carbon at a high temperature a i state the type of reaction that iron iii oxide undergoes in this extraction mark a ii write a half equation for the reaction of the iron iii ions in this extraction mark b at a high temperature carbon undergoes combustion when it reacts with oxygen b i suggest why it is not possible to measure the enthalpy change directly for the following combustion reaction c s graphite o g co g mark b ii state hess s law mark b iii state the meaning of the term standard enthalpy of combustion marks extra space wmp jan chem do not write outside the box c use the standard enthalpies of formation in the table below and the equation to calculate a value for the standard enthalpy change for the extraction of iron using carbon monoxide fe o s co g h f kj mol fe l co g fe o s co g fe i co g marks extra space d i write an equation for the reaction that represents the standard enthalpy of formation of carbon dioxide mark d ii state why the value quoted in part c for the standard enthalpy of formation of co g is the same as the value for the standard enthalpy of combustion of carbon mark turn over wmp jan chem

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