CAIE A Level Chemistry 9701 · Nitrogen and sulfur
Oxides of nitrogen are present in the exhaust gases of internal combustion engines and are removed by catalytic converters.
Describe the natural and man-made origins of these oxides, and describe how a catalytic converter removes them from exhaust gases.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.