Motor gasoline is typically treated with about ______________ c.c. of tetraethyl lead per gallon to boost its octane rating?
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Answer: A. 3
Explanation
Motor gasoline was historically treated with tetraethyl lead to effectively boost the octane rating. Engine knocking is suppressed by adding about three cubic centimeters of lead per gallon. Small volumetric additions of tetraethyl lead dramatically improved the anti-knock performance of fuels. Tetraethyl lead is an organolead compound with the chemical formula C8H20Pb used historically. The compound acts as an effective antiknock agent to prevent premature ignition in engines. Lead additives were phased out globally due to severe environmental and public health hazards.
High compression engines require higher octane ratings to prevent damaging engine knock during operation. Modern refineries now use alternative oxygenates and severe reforming to achieve high octane numbers. Historical automotive fuels relied heavily on lead additives before environmental regulations took effect. Option B suggests an excessively high volume that would completely foul internal combustion engines. Option C represents an unrealistic concentration that exceeds total liquid volume limitations entirely. Option D specifies a quantity far too large for standard fuel treatment additive practices.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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