Question

What will be the product when ${{C}_{10}}{{H}_{22}}$ is used in a cracking process.

Answer 1

Hint: The answer to this question here is based on the basic concept of chemistry which includes the fact that cracking is nothing but thermal decomposition which gives simpler products on decomposition. The equation gives the correct answer.

Complete Solution :
In the lower classes, we have come across the petrochemicals and the process of producing various petroleum products based on fractional distillation too.
Now, here in this question cracking process is nothing but the application of heat energy to break the bonds and which yield the simpler molecules.
- Thermal cracking or simply cracking involves breaking down complex organic molecules that are long chain hydrocarbons into smaller components that are lighter hydrocarbons by the process involving breakage of carbon – carbon double bonds present in the precursors.
- The simpler molecules obtained are the useful hydrocarbon molecules among them some of which are unsaturated molecules.
- Cracking on the other hand is an important process as it helps to match supply of the fractions with greater demand for them.
Now, decane that is ${{C}_{10}}{{H}_{22}}$ is prior boiled and the gases produced are passed over hot powdered aluminium oxide catalyst which helps to provide convenient surface for hydrocarbon gases to crack and the decane thus breaks into octane and ethane as,
\[{{C}_{10}}{{H}_{22}}\to {{C}_{8}}{{H}_{18}}+{{C}_{2}}{{H}_{4}}\]

Thus, the correct answer is cracking of ${{C}_{10}}{{H}_{22}}$ gives octane and ethane.

Note: This process of cracking not only involves cracking of alkanes but also of alkenes and some members of this homologous series. Therefore, the same process is applied when the questions regarding alkenes and homologous series are given.