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  9. Q84

BPSC (Bihar PCS) 2025 · Question 84 of 145

Which compound is used for an increase of octane rating?

Miscellaneous

  1. ATetramethyl Oxide
  2. BTrimethyl hexane
  3. CTetraethyl leadCorrect
  4. DTriethyl toluene

Answer: C. Tetraethyl lead

Explanation

Tetraethyl lead (TEL) was once added to petrol as an anti-knocking agent to increase the octane rating of fuel. A higher octane rating prevents premature ignition ("knocking") in internal combustion engines, improving efficiency and performance.

Source: 71st BPSC CCE Prelims 2025 (Set H)

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