Final answer:
When combining the two given intermediate chemical reactions, oxygen (O2) appears as a reactant in the final chemical equation, which is C(s) + O2(g) → CO2(g).
Step-by-step explanation:
The student's question involves how oxygen will appear in the final chemical equation after adding two intermediate chemical reactions. These reactions are:
C(s) + 1⁄2 O2(g) → CO(g)
CO(g) + 1⁄2 O2(g) → CO2(g)
When we add these reactions together, we get:
C(s) + O2(g) → CO2(g)
In this final equation, we can see that oxygen is completely used up in the process of forming carbon dioxide from carbon. Therefore, in the final chemical equation, oxygen (O2) appears as a reactant.