AQA Jun 2012 Paper 5 Q4

Answers available below

do not write outside the box the oxides nitrogen monoxide no and nitrogen dioxide no both contribute to atmospheric pollution the table gives some data for these oxides and for oxygen s j k mol hf kj mol o g no g no g nitrogen monoxide is formed in internal combustion engines when nitrogen monoxide comes into contact with air it reacts with oxygen to form nitrogen dioxide no g o g no g a calculate the enthalpy change for this reaction marks b calculate the entropy change for this reaction marks wmp jun chem do not write outside the box c calculate the temperature below which this reaction is spontaneous marks d suggest one reason why nitrogen dioxide is not formed by this reaction in an internal combustion engine mark e write an equation to show how nitrogen monoxide is formed in an internal combustion engine mark f use your equation from part e to explain why the free energy change for the reaction to form nitrogen monoxide stays approximately constant at different temperatures marks turn over wmp jun chem

Show answer