Final answer:
In the cracking process, small short-chain hydrocarbons are created from long-chain hydrocarbons to produce more valuable and volatile products like gasoline. Cracking, which involves heating to high temperatures, is distinct from reforming, which chemically alters alkanes for different uses.
Step-by-step explanation:
In the process of cracking, small short-chain hydrocarbons are produced from long-chain hydrocarbons. Cracking is commonly used in the petroleum refining industry to break down larger, less volatile and lower-value hydrocarbons into smaller, more volatile and higher-value products, such as gasoline. This transformation is achieved by heating the long-chain hydrocarbons to high temperatures, sometimes as high as 900°C. This causes the carbon-carbon bonds in the larger molecules to break, creating light hydrocarbons.
Cracking differs from another process called reforming, which involves the chemical conversion of straight-chain alkanes to either branched-chain alkanes or mixtures of aromatic hydrocarbons. Alkanes, being saturated hydrocarbons, serve as excellent fuels and are found in products like natural gas, camping stove butane, gasoline, kerosene, diesel oil, and fuel oil. They are usually obtained from crude oil via fractional distillation, which takes advantage of the differences in boiling points between various components of the oil.