Final answer:
The energy released upon the combustion of 1 mole of fuel is generally higher for substances with more carbon atoms. From the given options, propane (C₃H₈) releases the most energy per mole upon combustion, based on the enthalpy of combustion, which is −-22219.2 kJ/mol. Therefore, propane is the correct answer to the question.
Step-by-step explanation:
The question concerns the energy released upon the combustion of one mole of various fuels. The combustion process for each of the given substances generally follows the formula of the fuel reacting with oxygen to produce carbon dioxide and water, releasing energy in the form of heat. The change in enthalpy (ΔH) for each combustion reaction, also known as the enthalpy of combustion, would allow us to compare which fuel releases the most energy.
Hydrogen (H₂) releases a substantial amount of energy upon combustion, but this is for two moles of water formation. The combustion of methane (CH₄), propane (C₃H₈), and ethanol (C₂H₅OH) follow similar patterns but produce a varying number of moles of CO₂ and H₂O, and thus different amounts of energy per mole of fuel burned.
The enthalpy of combustion is typically higher for substances with more carbon atoms, assuming complete combustion. Therefore, without specific numerical data provided, we can infer that among the given options, propane (C₃H₈), which has a greater number of carbon atoms than methane or hydrogen and a simpler structure than ethanol, potentially releases the highest energy upon the combustion of 1 mole under standard conditions.
To back this up with numbers, the heat of combustion of propane is −-22219.2 kJ/mol, which is quite high. This data suggests that propane (C₃H₈) would be the correct answer based on its higher enthalpy change from the given options when burned.
Therefore, the MCQ answer in the final answer for the question "Among the gases given in the options, which gas liberates the highest energy on the combustion of 1 mole?" is (c) Propane (C₃H₈).