20. Why is ethanol added to gasoline?

Can't find this answer in my book, and I've gone back and checked for it like three times. Please and thank you!

Ethanol is added to gasoline for several reasons:

1. Oxygenation: Ethanol contains oxygen, which helps in the combustion process by increasing the amount of available oxygen for the reaction. This leads to more complete and efficient combustion, resulting in reduced emissions of harmful pollutants.

2. Octane rating: Ethanol has a high octane rating, typically around 100. Adding ethanol to gasoline increases the overall octane rating of the fuel blend. Higher octane ratings reduce the likelihood of engine knocking, which can damage the engine and decrease performance.

3. Renewable energy source: Ethanol is produced from renewable resources, such as corn or sugarcane, which makes it a more sustainable alternative to petroleum-based fuels. As the world seeks to reduce dependence on fossil fuels and combat climate change, ethanol offers an environmentally friendly option.

4. Energy diversification: By blending ethanol with gasoline, it helps to diversify the energy sources used in transportation. This reduces reliance on crude oil, promotes energy security, and encourages the growth of the biofuels industry.

As for finding the answer outside your book, you can try the following resources to gather more information:

1. Online sources: Use search engines, such as Google, to find reliable websites or articles that explain the purpose of adding ethanol to gasoline. Websites like the Environmental Protection Agency (EPA) or the Department of Energy (DOE) often provide detailed information on this topic.

2. Academic journals: Access online databases or library resources to search for research papers or studies related to ethanol-gasoline blends. These sources often provide in-depth analysis and scientific explanations.

3. Industry publications: Look for articles or reports from reputable sources in the automotive or energy industry. Magazines like "Automotive News" or "Energy Policy" may contain relevant information.

Remember to evaluate the credibility of the sources you find by checking for author credentials, publishing date, and peer-review status.