MAE 115 Combustion (40 points): Applied Engineering Thermodynamics 21 July 2022 3. A mixture of 1 kmol Methane (CH4) and 80% excess air, both originally at 350 K, are combusted at a constant pressure of 1 atm Determine the following: (a) The balanced chemical reaction if complete combustion occurs (b) The equivalence ratio (c) Using the table below, calculate how much energy is present in the reactants only (d) You need to calculate the adiabatic flame temperature for this mixture. You're first temperature guess produces a total combustion products enthalpy of -40,000 kJ/kmol. Based on the reactant enthalpy calculated in (c), should your next temperature guess be higher or lower? (e) If combustion were incomplete, and CO existed in the products, what system of equations (neglecting the first law for a reacting system) would be used to solve for the concentration of products? Assume the only dissociation to create CO is the following the equilibrium reaction: CO CO+ 02. (f) If the air and methane mixture were initially heated to 600 K before any chemical reaction occurred, would the adiabatic flame temperature increase, decrease, or remain the same? Provide a one sentence explanation for your answer. Would the adiabatic flame temperature increase or decrease if the combustion occurred at constant volume? Provide a one sentence explanation for your answer. BOX ALL ANSWERS Species 0 Enthalpy of formation, Enthalpy at 298 K CH4 02 N2 (kJ/kmol) -74,850 0 0 (kJ/kmol) Enthalpy at 350 K (kJ/kmol) 11,744 13,824 8,682 10,213 8,669 10,180