Diesel fuel (C12H26) at 25C is burned in a steady flow combustion chamber with 20 percent excess

Question:

Diesel fuel (C12H26) at 25°C is burned in a steady flow combustion chamber with 20 percent excess air that also enters at 25°C. The products leave the combustion chamber at 500 K. Assuming combustion is complete determine the required mass flow rate of the diesel fuel to supply heat at a rate of 2000 kJ/s. Answer: 49.5 g/s