MCQ Detailed View

Tetraethyl lead (TEL) is an organometallic compound with the chemical formula (C₂H₅)₄Pb. It is primarily used as an additive in petrol (gasoline) to improve engine performance. TEL increases the octane number of fuel, which helps prevent engine knocking — a phenomenon where fuel combusts prematurely, causing reduced efficiency and engine damage.

TEL works by decomposing during combustion to form lead oxides, which react with other combustion byproducts to prevent knocking. This property made it a widely used additive in petrol during much of the 20th century.

Although TEL is an organic compound, it contains lead, a heavy metal, making it toxic to humans and the environment. Its use has been reduced or banned in many countries due to the harmful effects of lead emissions, which can cause neurological problems, especially in children, and contaminate air, soil, and water.

Other options listed are incorrect: TEL is not a pain killer, fire extinguisher, or mosquito repellent. Its main application is in fuel technology, specifically as an anti-knock agent in petrol.

Understanding the use of Tetraethyl Lead connects organic chemistry principles with real-world applications in energy and engineering. It also highlights the importance of considering the environmental and health impacts of chemical additives. TEL is a classic example studied in organic and industrial chemistry to demonstrate how chemical compounds are modified for practical use, while also considering safety and environmental regulations.