how many moles of CO2 are produced if 6 moles of O2 are used?
C6H12O6 +6O2 > 6CO2 + 6H2O
The equation given will show you the ratio for CO2 and O2. For every 6CO2, there is 6O2. Therefore, their ratio is 1:1, which means they share the same amount of moles.
Moles of CO2: 6 moles