Which organic compound is produced by fer- mentation and is used to replace fossil petrol?

Options

A. Ethanol
B. Butanol
C. Methanol
D. Propanol

Answer

To answer the question regarding which organic compound is produced by fermentation and is used to replace fossil petrol, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Fermentation**:
- Fermentation is an anaerobic process where glucose (a type of sugar) is broken down in the absence of oxygen.
- This process is primarily facilitated by yeast, which is a unicellular eukaryotic organism.

2. **Products of Fermentation**:
- The main products of fermentation include alcohol and carbon dioxide.
- The specific type of alcohol produced can vary depending on the conditions and the organisms involved.

3. **Identifying the Alcohols**:
- The question provides four options: ethanol, butanol, methanol, and propanol.
- Among these, ethanol (C2H5OH) is the most commonly produced alcohol through fermentation, especially by yeast.

4. **Ethanol as a Fuel**:
- Ethanol is widely recognized as a biofuel and is used as an alternative to fossil fuels like petrol.
- It can be blended with gasoline or used in its pure form in some vehicles.

5. **Conclusion**:
- Based on the fermentation process and the products involved, the organic compound produced by fermentation that is used to replace fossil petrol is **ethanol**.

### Final Answer:
**Ethanol** is the organic compound produced by fermentation and used to replace fossil petrol.

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