What is the product formed when ethyl bromide reacts with lead–sodium alloy?

Tetraethyl lead

The answer is (2) Tetraethyl lead.

Ethyl bromide reacts with lead–sodium alloy to form tetraethyl lead, a colorless, viscous liquid that is used as an antiknock agent in gasoline. The reaction is as follows:

Tetraethyl lead is a highly toxic compound and is no longer used in gasoline in most countries. However, it is still used in some countries, such as Mexico and China.

Therefore, the correct answer is (2).