Question

Octane number of petrol can be improved by adding or mixing it with which of the following chemicals ?
(A) $E{t_4}Pb$
(B) $C{H_3}OC{(C{H_3})_3}$
(C) 1-methyl naphthalene
(D) Pyrene.

Answer 1

To solve this question we should know the theory of Octane number to increase the Octane number of petrol we should add some chemicals called antiknock agents. These antiknock agents make oxidation of the petrol and increase the quality of the petrol.

Complete answer: By adding the antiknock agents to the petrol the number of carbon atoms will increase and the chain of carbon become bigger.
Octane number of petrol can be increased by adding some small amount of certain chemicals known as anti-knock agents or compounds, e.g. tetraethyl lead (TEL or $E{t_4}Pb$ ) . These mixtures of anti-knock agents and petrol are known as leaded petrol because the agent is of lead mixture.
In the modern days some special types of anti-knock agents are used to increase the octane number of petrol by increasing the number of carbons in the chain known as methyltert-butyl ether ( $C{H_3}OC{(C{H_3})_3}$). This antiknock agent is used to increase the octane rating because its oxygen helps gasoline to burn more completely and optimizes the oxidation during combustion.

Hence, the correct answer will be option number A and B.

Note: Octane number is used to increase the quality of petrol . By knowing the octane number of petrol we can compare the one petrol quality to other.By octane number we can differentiate the petrol.