Tetraethyl lead is a

Options

A. Solvent
B. Petroleum additive
C. Oxidising agent
D. Fire extinguisher

Answer

### Step-by-Step Solution:

1. **Identify the Compound**: Tetraethyl lead (TEL) is an organometallic compound. It consists of a lead atom (Pb) bonded to four ethyl groups (C2H5).

2. **Chemical Formula**: The chemical formula for tetraethyl lead can be represented as Pb(C2H5)4. This indicates that one lead atom is attached to four ethyl groups.

3. **Function of Tetraethyl Lead**: Tetraethyl lead is primarily used as an additive in gasoline (petrol). Its main function is to act as an anti-knocking agent.

4. **Mechanism of Action**: When gasoline is combusted, tetraethyl lead decomposes to form lead oxide (PbO). This lead oxide helps to prevent knocking during combustion, which is a form of premature ignition that can damage engines.

5. **Effect on Octane Rating**: By preventing knocking, tetraethyl lead increases the octane rating of the fuel. A higher octane number indicates better fuel performance and efficiency.

6. **Conclusion**: Tetraethyl lead enhances the quality of gasoline by improving its combustion characteristics and preventing engine knocking.