We say that the limiting reactant is the one that gets consumed first in a reaction and therefore limits the production of products.
Here we burn a candle made of wax with oxygen from the air, and it is `produced energy, CO2, and water.
If we limit the amount of oxygen in the available air, the candle's flame eventually goes out once it uses up all the O2.
O2 molecule of
Answer: the limiting reactant is the O2 from the air.