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A-LevelChemistryElectrochemistry9701/12 · Feb/Mar 2021 · Q181 Mark

NO, NO₂, CO and unburnt hydrocarbons are present in the exhaust gases of internal combustion engines. When catalytic converters are used to remove these compounds from the exhaust gases, redox reactions occur. What happens to each compound in the catalytic converter? NO NO₂ CO unburnt hydrocarbons A oxidised oxidised reduced oxidised B oxidised oxidised oxidised oxidised C reduced reduced oxidised oxidised D reduced reduced reduced reduced

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ANO oxidised, NO₂ oxidised, CO reduced, unburnt hydrocarbons oxidised
BNO oxidised, NO₂ oxidised, CO oxidised, unburnt hydrocarbons oxidised
CNO reduced, NO₂ reduced, CO oxidised, unburnt hydrocarbons oxidised
DNO reduced, NO₂ reduced, CO reduced, unburnt hydrocarbons reduced

✓ Correct answer

C: NO reduced, NO₂ reduced, CO oxidised, unburnt hydrocarbons oxidised

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About this question

Topic
Electrochemistry, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source
A-Level Chemistry, Feb/Mar 2021 Paper 1 Variant 2, question 18.

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