Chapter 7

A mixture of gases contains \(44 \mathrm{~kg}\) of \(\mathrm{CO}_{2}, 112 \mathrm{~kg}\) of \(\mathrm{N}_{2}\), and \(32 \mathrm{~kg}\) of \(\mathrm{O}_{2}\) at a mixture temperature of \(T_{\mathrm{m}}=287 \mathrm{~K}\) and the mixture pressure is \(p_{\mathrm{m}}=1\) bar. Calculate (a) number of moles of carbon dioxide, nitrogen, and oxygen (b) mole fraction of carbon dioxide (c) partial pressure of constituent gases, i.e., \(\mathrm{CO}_{2}, \mathrm{~N}_{2}\), and \(\mathrm{O}_{2}\) (d) mixture molecular weight \(\mathrm{MW}_{\mathrm{m}}\) (e) volume fraction of the constituent gases

Write the chemical reaction for the combustion of hydrogen, \(\mathrm{H}_{2}\), and air then calculate the stoichiometric fuelto-air ratio \(f_{\text {stoich }}\).

A gas is a mixture of \(22 \% \mathrm{O}_{2}, 33 \% \mathrm{~N}_{2}\), and \(45 \% \mathrm{CO}_{2}\) by volume. Calculate (a) the mole fraction of the constituents in the mixture (b) the mixture molecular weight \(\mathrm{MW}_{\mathrm{m}}\)

Write the chemical reaction for the complete combustion of JP-4 and air. JP-4 has the formula \(\mathrm{CH}_{1.93}\). Also, calculate the stoichiometric fuel- to-air ratio for this blended jet fuel.

Consider burning methane \(\left(\mathrm{CH}_{4}\right)\) with \(110 \%\) theoretical air. Calculate the equivalence ratio for this reaction. Assume that the nitrogen and the excess oxygen do not dissociate and/or chemically react to form new compounds.

One mole of oxygen, \(\mathrm{O}_{2(\mathrm{~g})}\), is heated to \(4000 \mathrm{~K}\) at the pressure of \(p_{m}\). A fraction of the oxygen dissociates to oxygen atoms according to $$ x \mathrm{O}_{2} \rightarrow 2 x \mathrm{O} $$ Assuming a state of equilibrium is reached in the mixture, calculate (a) mole fraction of \(\mathrm{O}_{2}\) at equilibrium when \(p_{m}\) is \(1 \mathrm{~atm}\). (b) mole fraction of \(\mathrm{O}_{2}\) at equilibrium when \(p_{m}\) is \(10 \mathrm{~atm}\). Assume the equilibrium constant for the reaction $$ \mathrm{O}_{2} \leftrightarrow 2 \mathrm{O} $$ is \(K_{p}=2.19\) atm at the temperature of \(4000 \mathrm{~K}\). Explain the effect of pressure on dissociation.

A combustion chamber uses a prediffuser with a sudden area expansion (known as a dump diffuser) to decelerate the flow of air \((\gamma=1.4)\) before entering the combustor. Assuming the inlet Mach number to the dump diffuser is \(M_{1}=0.5\), the area ratio of the dump diffuser is \(A_{2} / A_{I}=2.0\), calculate (a) exit Mach number \(M_{2}\) (b) the ratio of total pressures, i.e., \(p_{\mathrm{t} 2} / p_{\mathrm{t} 1}\)

Stoichiometric flame temperature for the combustion of methane in oxygen at \(1 \mathrm{~atm}\) pressure and at reference temperature of \(298 \mathrm{~K}\) is listed as \(3030 \mathrm{~K}\) in Table 7.4. The combustion of methane in air would produce the stoichiometric flame temperature of \(2210 \mathrm{~K}\). Explain the difference.

Consider a coaxial dump diffuser with area ratio \(A_{2} / A_{1} .\) Assuming that the static pressure acting on the sudden expansion wall \(p_{w}\) is the same as the inlet static pressure \(p_{1}\) and wall friction may be neglected, apply the conservation principles to show that $$ \frac{\Delta p_{\mathrm{t}}}{\rho V_{1}^{2} / 2}=\left(1-\frac{A_{1}}{A_{2}}\right)^{2} $$ in the limit of incompressible fluid.

We model an afterburner as a constant-area duct with a series of bluff bodies in the stream with a known drag coefficient. Assuming the following inlet conditions for dry mode Inlet Mach number \(M_{\mathrm{i}}=0.3\) \(\gamma_{\mathrm{i}}=\gamma_{\mathrm{e}}=1.33\) and \(c_{p \mathrm{i}}=c_{p \mathrm{e}}\) flameholder drag coefficient \(C_{\mathrm{D}}=0.5\) Calculate (a) static pressure ratio \(p_{e} / p_{i}\) (b) exit Mach number \(M_{\mathrm{e}}\) (c) static temperature ratio \(T_{e} / T_{i}\) (d) total pressure ratio \(p_{\mathrm{te}} / p_{\mathrm{ti}}\)

Atmospheric ozone is depleted through catalytic intervention of nitric oxide, NO. NO emissions in the upper atmosphere are estimated to be \(\sim 30 \mathrm{~g} / \mathrm{kg}\) fuel from hightemperature engines, overextended cruise periods. A supersonic transport carries \(50,000 \mathrm{~kg}\) of fuel at takeoff. Assuming \(90 \%\) of the fuel is consumed during cruise calculate the amount of nitric oxide emissions for a round trip flight. Now, multiply that by 360 round trips per year to estimate the (NO) pollution (of one aircraft) per year. Finally, what is the environmental impact ofa fleet of 100 aircraft?

Carbon monoxide is a byproduct of incomplete combustion of hydrocarbon fuels and is considered to be a pollutant. It is also a fuel capable of reacting with air to produce an adiabatic flame temperature of \(\sim 2400 \mathrm{~K}\) at the pressure of \(1 \mathrm{~atm}\) (Table 7.4). The stoichiometric combustion of carbon monoxide and air may be described by the following reaction: $$ \mathrm{CO}_{(\mathrm{g})}+1 / 2\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+(3.76 / 2) \mathrm{N}_{2(\mathrm{~g})} $$ Use conservation of energy principles applied to the above stoichiometric reaction to show that the adiabatic flame temperature of carbon monoxide is indeed \(\sim 2400 \mathrm{~K}\) in a reaction with air at 1 atmospheric pressure. You may use Table \(7.1\) for standard heats of formation and Table \(7.2\) for molar specific heats of various gases. Assume the reactants enter the combustion chamber at \(T_{f}=\) \(298.16 \mathrm{~K}\).

Write the stoichiometric combustion of methanol \(\left(\mathrm{CH}_{3} \mathrm{OH}\right)\) in (dry) theoretical air. If the lower heating value, LHV, of methanol is \(21.2 \mathrm{MJ} / \mathrm{kg}\), calculate its higher heating value, HHV.

Calculate the adiabatic flame temperature in the following reaction of octane in dry air at reference temperature \(\left(T_{\mathrm{f}}=298.16 \mathrm{~K}\right)\) and pressure (1 bar), $$ \begin{aligned} \mathrm{C}_{8} \mathrm{H}_{18(1)}+14\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \rightarrow & 8 \mathrm{CO}_{2(\mathrm{~g})}+9 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})} \\ &+\frac{3}{2} \mathrm{O}_{2(\mathrm{~g})}+14(3.76) N_{2(\mathrm{~g})} \end{aligned} $$ Assume the average molar specific heats of the chemical compounds at constant pressure are: $$ \begin{aligned} &\bar{c}_{p_{\mathrm{CO}_{2}}}=54.31 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \quad \bar{c}_{p_{\mathrm{O}_{2}}}=34.88 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ &\bar{c}_{p_{\mathrm{N}_{2}}}=32.7 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \quad \bar{c}_{p_{\mathrm{H}_{2} \mathrm{O}}}=41.22 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \end{aligned} $$ The standard heats of formation in this reaction are: $$ \begin{aligned} \left.\Delta \bar{h}_{f}^{o}\right|_{C_{8} H_{18(1)}} &=-249,930 \mathrm{~kJ} / \mathrm{kmol}, \\ \left.\Delta \bar{h}_{f}^{o}\right|_{\mathrm{H}_{2} \mathrm{O}(\mathrm{g})} &=-241,827 \mathrm{~kJ} / \mathrm{kmol}, \\ \left.\Delta \bar{h}_{f}^{o}\right|_{\mathrm{CO} 2(\mathrm{~g})} &=-393,522 \mathrm{~kJ} / \mathrm{kmol} \end{aligned} $$

In the combustion of gaseous hydrogen and gaseous oxygen, as described by $$ \mathrm{H}_{2(\mathrm{~g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow 0.95 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}+0.05 \mathrm{H}_{2(\mathrm{~g})}+0.025 \mathrm{O}_{2(\mathrm{~g})} $$ the reactants entered the combustion chamber at \(T_{1}=\) \(298.16 \mathrm{~K}\) and pressure of \(1 \mathrm{~atm}\). Assume: $$ \begin{aligned} &\left(\Delta \bar{h}_{f}^{0}\right)_{\mathrm{H}_{2} \mathrm{O}(\mathrm{g})}=-241,827 \mathrm{~kJ} / \mathrm{kmol} \quad \bar{c}_{p_{\mathrm{O}_{2}}}=37.8 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ &\bar{c}_{p_{\mathrm{H}_{2}}}=34.18 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \quad \bar{c}_{p_{\mathrm{H}_{2} \mathrm{O}}}=51.0 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \end{aligned} $$ Calculate the (a) heat of reaction, \(Q_{R}\), in \(\mathrm{kJ}\) (b) lower heating value, LHV, in \(\mathrm{kJ} / \mathrm{kg}\) (c) adiabatic flame temperature, \(T_{a f}\), in \(\mathrm{K}\)

Consider the combustion of butane and air according to $$ \begin{aligned} \mathrm{C}_{4} \mathrm{H}_{10}+8\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \rightarrow & 4 \mathrm{CO}_{2}+5 \mathrm{H}_{2} \mathrm{O} \\ &+1.5 \mathrm{O}_{2}+8(3.76) \mathrm{N}_{2} \end{aligned} $$ Calculate the (a) fuel-to-air ratio, \(f\) (b) equivalence ratio, \(\varphi\), for this reaction

Lean combustion of liquid \(n\)-decane (from the kerosene family) and air at a reference temperature of \(T_{f}=298.16 \mathrm{~K}\) and pressure of 1 bar is approximated by the following chemical reaction: $$ \begin{aligned} \mathrm{C}_{10} \mathrm{H}_{22(\mathrm{l})}+25\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \rightarrow & 10 \mathrm{CO}_{2(\mathrm{~g})}+11 \mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \\ &+\frac{19}{2} \mathrm{O}_{2(\mathrm{~g})}+25(3.76) \mathrm{N}_{2(\mathrm{~g})} \end{aligned} $$ Assuming the standard heats of formation in this reaction are: $$ \begin{aligned} \left.\Delta \bar{h}_{f}^{o}\right|_{\mathrm{C}_{10} \mathrm{H}_{22(\mathrm{l})}} &=-300,900 \mathrm{~kJ} / \mathrm{kmol} \\ \left.\Delta \bar{h}_{f}^{o}\right|_{\mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}} &=-241,827 \mathrm{~kJ} / \mathrm{kmol} \\ \left.\Delta \bar{h}_{f}^{o}\right|_{\mathrm{CO}_{2(\mathrm{~g})}} &=-393,522 \mathrm{~kJ} / \mathrm{kmol} \end{aligned} $$ and average molar specific heats at constant pressure are: $$ \begin{array}{ll} \bar{c}_{p_{\mathrm{CO}_{2}}}=54.31 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} & \bar{c}_{p_{\mathrm{O}_{2}}}=34.88 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ \bar{c}_{p_{\mathrm{N}_{2}}}=32.7 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} & \bar{c}_{p_{\mathrm{H}_{2} \mathrm{O}}}=41.22 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \end{array} $$ Calculate (a) the fuel-to-air ratio, \(f\), for this reaction (b) write the stoichiometric reaction for this fuel in air (c) the equivalence ratio, \(\phi\) (d) the adiabatic flame temperature, \(T_{a f}\), in \(\mathrm{K}\) in the first reaction (e) the Lower Heating Value (LHV) of this fuel, in \(\mathrm{kJ} / \mathrm{kg}\), in stoichiometric combustion in oxygen

Calculate the adiabatic flame temperature in the combustion reaction of octane in air at reference temperature \(\left(T_{f}=298.16 \mathrm{~K}\right)\) and pressure ( 1 bar), $$ \begin{aligned} \mathrm{C}_{8} \mathrm{H}_{18(l)}+18\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \rightarrow & 8 \mathrm{CO}_{2(\mathrm{~g})}+9 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}+\frac{11}{2} \mathrm{O}_{2(\mathrm{~g})} \\ &+18(3.76) \mathrm{N}_{2(\mathrm{~g})} \end{aligned} $$ You may assume the average molar specific heats of the compounds at constant pressure are: $$ \begin{array}{ll} \bar{c}_{p_{\mathrm{CO}_{2}}}=54.31 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} & \bar{c}_{p_{\mathrm{O}_{2}}}=34.88 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ \bar{c}_{p_{\mathrm{N}_{2}}}=32.7 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} & \bar{c}_{p_{\mathrm{H}_{2} \mathrm{O}}}=41.22 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \end{array} $$ The standard heats of formation in this reaction are listed in Table \(6.1\) in the book as: $$ \left.\Delta \bar{h}_{f}^{o}\right|_{\mathrm{C}_{8} \mathrm{H}_{18}_{(l)}}=-249,930 \mathrm{~kJ} / \mathrm{kmol}, $$ $$ \begin{aligned} \left.\Delta \bar{h}_{f}^{o}\right|_{\mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}} &=-241,827 \mathrm{~kJ} / \mathrm{kmol} \\ \left.\Delta \bar{h}_{f}^{o}\right|_{\mathrm{CO}_{2(\mathrm{~g})}} &=-393,522 \mathrm{~kJ} / \mathrm{kmol} \end{aligned} $$

Consider the flow in an afterburner, in dry mode, as shown. The flow upstream of the flameholder, i.e., the afterburner inlet, is characterized by: $$ \begin{aligned} &p_{1}=33 \mathrm{kPa}, \quad T_{1}=675 \mathrm{~K}, \quad M_{1}=0.3, \quad \dot{m}_{1}=100 \mathrm{~kg} / \mathrm{s} \\ &\gamma_{1}=1.33, \quad R_{1}=287 \mathrm{~J} / \mathrm{kgK} \end{aligned} $$ Assuming the flameholder drag coefficient is \(C_{\mathrm{D}}=1.0\), which is based on the duct cross-sectional area, and the flow is \(a d i\) abatic, calculate (a) the duct cross sectional area, \(A_{1}\), in \(m^{2}\) (b) flameholder drag, \(D_{\text {flameholder }}\), in \(\mathrm{kN}\) (c) static pressure in station 2, where \(M_{2}=0.371\), \(\gamma_{2}=\gamma_{1}=1.33\) and wall friction drag coefficient is neglected (i.e., \(C_{\mathrm{fw}}=0\) ) as shown (d) static temperature in station \(2, T_{2}\), in \(\mathrm{K}\)

Consider the stoichiometric combustion of one mole of octane in dry air, where the carbon in fuel is completely oxidized to form eight moles of \(\mathrm{CO}_{2}\) in the products, as shown in the following reaction $$ \begin{aligned} \mathrm{C}_{8} \mathrm{H}_{18(\mathrm{~g})}+\frac{25}{2}\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \rightarrow & 8 \mathrm{CO}_{2}+9 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})} \\ &+\frac{25}{2}(3.76) \mathrm{N}_{2} \end{aligned} $$ Assuming the reactants entered the combustion chamber at reference temperature of \(298.16 \mathrm{~K}\) and combustion takes place at reference pressure of 1 bar, calculate: (a) adiabatic flame temperature, \(T_{\mathrm{af}}(\mathrm{K})\), of octane in the above reaction Now, consider the same reactants at the same entrance condition and pressure engage in combustion that produces seven moles of carbon dioxide and one mole of carbon monoxide in the products of combustion, following $$ \begin{aligned} \mathrm{C}_{8} \mathrm{H}_{18(\mathrm{~g})}+\frac{25}{2}\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \rightarrow & 7 \mathrm{CO}_{2}+\mathrm{CO}+9 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})} \\ &+\frac{25}{2}(3.76) \mathrm{N}_{2}+\frac{1}{2} \mathrm{O}_{2} \end{aligned} $$ Calculate (a) the adiabatic flame temperature of octane in the second reaction (b) compare the two adiabatic flame temperatures and briefly comment on the cause for the difference $$ \begin{aligned} &\bar{c}_{p_{\mathrm{N}_{2}}}=33.6 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \quad \bar{c}_{p_{\mathrm{CO}_{2}}}=57.9 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ &\bar{c}_{p_{\mathrm{O}_{2}}}=37.8 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \quad \bar{c}_{p_{\mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}}}=42.3 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ &\bar{c}_{p_{\mathrm{CO}_{(\mathrm{g})}}}=36.27 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ &\left(\Delta \bar{h}_{f}^{0}\right)_{\mathrm{C}_{8} \mathrm{H}_{18(\mathrm{~g})}}=-208,447 \mathrm{~kJ} / \mathrm{kmol} \\ &\left(\Delta \bar{h}_{f}^{0}\right)_{\mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}}=-241,827 \mathrm{~kJ} / \mathrm{kmol} \\ &\left(\Delta \bar{h}_{f}^{0}\right)_{\mathrm{CO}_{2(\mathrm{~g})}}=-393,522 \mathrm{~kJ} / \mathrm{kmol} \\ &\left(\Delta \bar{h}_{f}^{0}\right)_{\mathrm{CO}_{(\mathrm{g})}}=-110,530 \mathrm{~kJ} / \mathrm{kmol} \end{aligned} $$

The chemical reaction of gaseous octane in air reaches an equilibrium state in a combustor that is described by: $$ \begin{aligned} \mathrm{C}_{8} \mathrm{H}_{18(\mathrm{~g})}+21\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \leftrightarrow & 7 \mathrm{CO}_{2}+\mathrm{CO}+9 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})} \\ &+9 \mathrm{O}_{2}+21(3.76) \mathrm{N}_{2} \end{aligned} $$ Assuming the reactants entered the combustor at the reference temperature ( \(298.16 \mathrm{~K}\) ) and pressure (1 atm), calculate the (a) fuel-to-air ratio, \(f\) (b) equivalence ratio, \(\varphi\) (c) adiabatic flame temperature, \(T_{a f}\), in \(\mathrm{K}\), at the combustor exit Assume the molar specific heats of the products are: $$ \begin{aligned} &\bar{c}_{p_{\mathrm{CO}_{2}}}=61.9 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K}, \bar{c}_{p_{\mathrm{O}_{2}}}=37.8 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K}, \\ &\bar{c}_{p_{\mathrm{N}_{2}}}=33.6 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K}, \\ &\bar{c}_{p_{\mathrm{H}_{2} \mathrm{O}}}=52.3 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K}, \bar{c}_{p_{\mathrm{CO}}}=29.2 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \end{aligned} $$

Consider the stoichiometric combustion of gaseous ethyl alcohol (or ethanol) in air, as shown: $$ \begin{aligned} \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}_{(\mathrm{g})} &+3.5\left(\mathrm{O}_{2}+3.76 \mathrm{~N}_{2}\right) \\ & \rightarrow 2 \mathrm{CO}_{2}+3 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}+(3.5)(3.76) \mathrm{N}_{2} \end{aligned} $$ Assuming the reactants entered the combustion chamber at reference temperature of \(298.16 \mathrm{~K}\) and combustion takes place at reference pressure of \(1 \mathrm{bar}\), calculate the (a) adiabatic flame temperature, \(T_{a f}\), in \(\mathrm{K}\), of ethanol in stoichiometric combustion (b) lower heating value (LHV) of ethanol in \(\mathrm{kJ} / \mathrm{kg}\) (c) higher heating value (HHV) of ethanol in \(\mathrm{kJ} / \mathrm{kg}\) $$ \begin{aligned} &\bar{c}_{p_{\mathrm{N}_{2}}}=33.6 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ &\bar{c}_{p_{\mathrm{CO}_{2}}}=61.9 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ &\left(\Delta \bar{h}_{f}^{0}\right)_{\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}_{(\mathrm{g})}}=-235,000 \mathrm{~kJ} / \mathrm{kmol} \\ &\bar{c}_{p_{\mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}}}=52.3 \mathrm{~kJ} / \mathrm{kmol} \cdot \mathrm{K} \\ &\left(\Delta \bar{h}_{f}^{0}\right)_{\mathrm{CO}_{2(\mathrm{~g})}}=-393,522 \mathrm{~kJ} / \mathrm{kmol} \\ &\left(\Delta \bar{h}_{f}^{0}\right)_{\mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}}=-241,827 \mathrm{~kJ} / \mathrm{kmol} \end{aligned} $$

Write the stoichiometric combustion of \(\mathrm{C}_{6} \mathrm{H}_{6}\) with (dry) theoretical air.

Consider the stoichiometric combustion of Jet-A fuel, \(\mathrm{C}_{12} \mathrm{H}_{23}\), in (dry) air. (a) Write the chemical reaction between Jet-A fuel and air in stoichiometric combustion (b) Calculate stoichiometric fuel-to-air ratio in this reaction