Why are alkanes cracked?

Cracking alkanes is primarily done to meet the demand for fuels. Alkanes, which are saturated hydrocarbons, can be high in molecular weight, making them less useful as fuels. Through the process of cracking, larger alkane molecules are broken down into smaller, more useful hydrocarbons, including both alkanes and alkenes.

Smaller molecules are typically more desirable as fuel because they tend to ignite more easily and burn more efficiently in engines and heating applications. This is particularly important given the fluctuating demand for different types of fuels in various sectors, such as transportation and industry. The production of lighter hydrocarbons from cracking helps in ensuring that there is a sufficient supply of fuels to meet this demand.

While alkenes are produced as a byproduct of this process, their generation is relevant in the context of fuel availability rather than being the primary motivation for cracking. Therefore, the option that emphasizes fulfilling the demand for fuels accurately captures the main reason for the cracking of alkanes.