Final answer:
The lower the oxidation state of a carbon molecule, the better it is as a fuel, as it can oxidize further during combustion to release more energy. Therefore, the correct option is B) Lower oxidation state makes the carbon molecule a better fuel.
Step-by-step explanation:
When considering the relationship between the oxidation state of a carbon molecule and its usefulness as a fuel, the key point is to understand how oxidation and reduction reactions affect the molecule's ability to release energy. A molecule's usefulness as a fuel is primarily associated with its ability to release energy through combustion. Combustion is an oxidation reaction where a fuel reacts with oxygen to release energy.
Carbon molecules with a lower oxidation state are generally better fuels. This is because carbon atoms in a lower oxidation state have more potential to form new bonds with oxygen during the combustion process. For instance, methane (CH₄) has a carbon with an oxidation state of −4 and upon combustion, can form carbon dioxide, where the carbon is at an oxidation state of +4. The change from −4 to +4 corresponds to a significant release of energy. Therefore, the correct option is B) Lower oxidation state makes the carbon molecule a better fuel.
In contrast, a higher oxidation state carbon molecule will have less potential to oxidize further and will thus release less energy upon combustion. Molecules like carbon dioxide, where the carbon atom is already in a high oxidation state of +4, cannot release any further energy through normal combustion processes, as they are already fully oxidized.