Answer:
The oxygen will appear in the final stage if the oxygen is excess from the beginning.
Step-by-step explanation:
1. C +(1/2)O2 —> CO
2. CO+(1/2)O2—> CO2
The first stage explains that the oxygen is limited and hence CO is produced.
The 2nd stage explains that if the oxygen is excess, then CO2 will be produced.
The overall reaction when oxygen is excess is given by:
C + O2 —> CO2