Question

Which of the following is used as an anti-knocking material?

• A. T.E.L
• B. ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$
• C. Glyoxal
• D. Freon

Answer 1

Answer: (A), (B)

${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

Explanation for correct option:

A. T.E.L

B. ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

Anti-knocking material:

• An Anti-knocking material is an additive that is used to reduce engine knocking and increase the fuel's octane rating.
• The best example of an anti-knocking agent is Tetraethyl lead (T.E.L).

Tetraethyl lead:

• The chemical formula of Tetraethyl lead is $\mathrm{Pb}{\left({\mathrm{C}}_2{\mathrm{H}}_5\right)}_4$.
• Tetraethyl lead is that it is used to enhance the octane number of fuel like gasoline.
• The more the octane number, the higher the efficiency of the fuel and the lower probability to produce a knocking sound.

Ethanol:

• Ethanol $\left({\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}\right)$ also serves as an anti-knocking agent that increases the octane number of gasoline.

Explanation for incorrect options:

C. Glyoxal is used as a solubilizer or cross-linking agent in the formation of polymers.

D. Feron is used in refrigerators.

Hence, the correct options are A and B.