Question

Which of the following compounds is used in antiknock compositions to prevent the deposition of oxides of lead on spark plug, combustion chamber and exhaust pipe.

• A. Glycerol
• B. Glycol
• C. 1, 2-dibromoethane
• D. Benzene

Answer 1

Answer: (C)

1, 2-dibromoethane

Answer 2

$\mathrm { Pb } \left( \mathrm { C } _ { 2 } \mathrm { H } _ { 5 } \right) _ { 4 } \xrightarrow { \text { heat } } \mathrm { Pb } + \underset { \text { Ethyl radical } } { 4 \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } }$

As leaded gasoline burns, lead metal gets deposited in the engine which is removed by adding ethylene dibromide. The lead bromide is volatile and is carried off with the exhaust gases from the engine.