Chapter 7, Problem 122IAE

Carbon dioxide emissions have been implicated as a major factor in climate change. Which of the following liquid fuels, when burned completely in oxygen at 25 °C, generates the smallest amount of CO₂per kilojoule of energy output?
Methanol, ${\text{CH}}_{\text{3}}\text{OH }\left({\Delta }_f{\text{H}}^{\circ }\text{ = -238}{\text{.7 kJ mol}}^{\text{-1}}\right);$ cetane, ${\text{C}}_{16}{\text{H}}_{\text{34}\left({\Delta }_f{\text{H}}^{\circ }\text{ = -456}{\text{.3 kJ mol}}^{\text{-1}}\right);}$ methyl linoleate, ${\text{C}}_{19}{\text{H}}_{\text{34}}{\text{O}}_2\left({\Delta }_f{H}^{\circ }=-604.9kJmo{l}^{-1}\right)$ ; octane, ${\text{C}}_{18}{\text{H}}_{\text{18}}\left({\Delta }_f{H}^{\circ }=-250.1kJmo{l}^{-1}\right)$ .
The ${\Delta }_f{H}^{\circ }$ values for CO₂(g) and H₂O(I) are -393.5 and -285.8 kJ mol-1, respectively.