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A 5 L mixture containing methane and propane is completely burned at 0°C and 1 atm. If 16 L of oxygen, measured at the same temperature and pressure, is used up, what is the heat evolved in this combustion, in kJ? (Given: ΔHcomb(CH₄) = 890 kJ mol⁻¹ and ΔHcomb(C₃H₈) = 2220 kJ mol⁻¹)

1. 32
2. 38
3. 317
4. 477

Correct answer: 317

Solution

The correct option is derived from calculating the moles of methane and propane in the mixture based on the stoichiometry of their combustion reactions with oxygen. By determining the amount of each gas burned and applying their respective enthalpy changes of combustion, the total heat evolved can be accurately calculated, leading to the correct answer of 317 kJ.

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