One way to evaluate fuels with respect to global warming is to determine how much heat they release during combustion relative to how much CO₂ they produce. The greater the heat relative to the amount of CO₂, the better the fuel. Use the combustion reactions of carbon, natural gas, and octane, in combination with the enthalpy of combustion for each reaction (all given earlier), to calculate the heat (in kJ) released by each fuel per 1.00 kg of CO₂ produced.

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SORT You are given the mass of CO₂ emitted and asked to find the energy output for three different fuels. STRATEGIZE First write the thermochemical equations for the combustion of each fuel given in Section 7.10. The conceptual plan has two parts. In the first part, use the molar mass of CO₂ to convert from mass of CO₂ to moles of CO₂. This step is the same for each fuel. In the second part, use the stoichiometric relationship between moles of CO₂ produced and kilojoules of energy released to calculate the energy output. Repeat the second part for each fuel using the appropriate stoichiometric relationship from the balanced equations. GIVEN: 1.00 kg CO₂ FIND: KJ C(s) + O₂(g) → CO₂(g) CH4(g) + 2O2(8) CO₂(g) + 2 H₂O(g) C8H18(1) + 25/2 02(8) → 8 CO₂(g) + 9 H₂O(g) CONCEPTUAL PLAN kg CO₂ mol CO₂ 1000 g 1 kg kJ 1 mol fuel g CO₂ kJ AHixn = 1 mol 44.01 g AHixn = -802.3 kJ -393.5 kJ AHixn=-5074.1 kJ mol CO₂ This conversion factor, based on the following stoichiometric relationships, is different for each fuel.