Sure, let's analyze the problem step by step.
1. Understanding Octane Rating of Ethanol:
- Pure ethanol has an octane rating of about 113.
2. Composition of E85:
- E85 is a type of fuel blend that typically contains 85% ethanol and 15% gasoline (by volume), but for this specific question, we also know it has 35% oxygen content by weight.
3. Octane Rating Considerations:
- The octane rating of a fuel blend is influenced by its components. Since ethanol has a high octane rating (113), we might expect that adding ethanol to gasoline will increase the overall octane rating compared to pure gasoline.
4. Impact of Oxygen Content:
- The presence of oxygen in the fuel can affect combustion efficiency. Higher oxygen content typically results in better combustion but does not directly correlate to a proportional increase in the octane rating. The adjustment in octane rating for fuel blends with oxygen-containing compounds (like ethanol) is a bit more complex.
Given the above points, let's look at the options:
- A. 110-115: This would be close to the octane rating of pure ethanol, which is unlikely given the mix with gasoline.
- B. 100-105: This range is higher but still seems on the high side for an 85% ethanol blend.
- C. 90-95: This feels reasonable as it accounts for the dilution with gasoline.
- D. 98-100: This range is also possible but might be slightly higher than expected for a blend.
Considering all these facets, the most suitable and balanced estimate for the octane rating of E85 from the options provided is:
C. 90-95.
