Saturated liquid butane (note: use generalized charts) enters an insulated constant pressure combustion chamber at 25C, and

Question:

Saturated liquid butane (note: use generalized charts) enters an insulated constant pressure combustion chamber at 25°C, and x times theoretical oxygen gas enters at the same pressure and temperature. The combustion products exit at 3400 K. Assuming that the products are a chemical equilibrium gas mixture that includes CO, what is x?