The self-extinction of candle flames in sealed environments is used as the foundation of a guided-inquiry module suitable for first-year chemistry labs. Working in groups of three or four, students are introduced to gas chromatography by resolving and identifying the O2 and N2 peaks from ambient air samples. The separation takes less than two minutes, permitting each student to gain hands-on experience. When the students are comfortable with the instrument, they are provided with the materials needed to construct a sample chamber and measure the composition of the air remaining after a candle flame has burned out. Students are initially surprised by the quantity of O2 remaining, which is typically found to be 14% to 16%. Through interaction with the laboratory instructor the students attempt to improve their experimental design and reproduce their best results to allow some estimate of the remaining error in their method. Finally, they are asked to explain their results and apply them in other contexts.
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MacNeil et al. (2003) studied this question.