Methane (CH4) is the major component of natural gas. 2.5 moles of methane were placed in a commercial colorimeter and subjected to a combustion reaction. The reaction released 2800 kJ of energy.

Question

Compare this energy value to the energy values of paraffin and diethylene glycol. Is methane a good choice as a fuel?

Answer 1

So you know 2.5 mols CH$ releases 2800 kJ of energy. (By the way that is calorimeter).
Look up the energy values for paraffin and the glycol and compare them. That's all there is to it. You can find that information on Google.