An illustrative example of a cracking reaction is the decomposition of long-chain hydrocarbons into smaller, more useful molecules.

Cracking is a vital process in the petrochemical industry, employed to transform large, complex hydrocarbons into smaller, more practical molecules. This transformation is accomplished by applying heat and pressure, and sometimes utilizing a catalyst. A specific example of a cracking reaction involves the breakdown of decane, a long-chain hydrocarbon, into octane and ethene. The chemical equation representing this reaction is:

In this reaction, decane ($\text{C}_{10}\text{H}_{22}$), a component of crude oil, is subjected to high temperatures, resulting in its decomposition into octane ($\text{C}_{8}\text{H}_{18}$) and ethene ($\text{C}_{2}\text{H}_{4}$). Octane is a key component of petrol, while ethene is an essential building block in the production of plastics and various chemicals.

Cracking reactions are crucial in the petrochemical industry as they enable us to maximize the utility of hydrocarbons found in crude oil. Many of these hydrocarbons are too large and complex to be valuable on their own. By breaking them down into smaller molecules, we can produce fuels and other valuable products.

Additionally, cracking helps to balance the supply and demand for various types of hydrocarbons. For instance, there is a high demand for petrol and other short-chain hydrocarbons, whereas the demand for long-chain hydrocarbons is relatively lower. By cracking long-chain hydrocarbons, we can enhance the supply of short-chain hydrocarbons to meet this demand.

It is important to note that cracking is an example of a thermal decomposition reaction, wherein a compound is broken down into simpler substances through heating. This process is essential in the petrochemical industry, allowing us to optimize our use of natural resources.