it is possible to obtain oxygen from air by fractional distillation because

Options

A. oxygen is in a different group of the periodic table from nitrogen
B. oxygen in more reactive than nitrogen
C. oxygen has higher boiling point than nitrogen
D. oxygen has a lower density than nitrogen

Explanation

To answer the question of whether it is possible to obtain oxygen from air by fractional distillation, we need to analyze the properties of the gases present in air and the principles of fractional distillation.

### Step-by-Step Solution:

1. **Understanding Air Composition**:
- Air is primarily composed of nitrogen (approximately 78%), oxygen (approximately 21%), argon (approximately 0.93%), and trace amounts of other gases.

2. **Principle of Fractional Distillation**:
- Fractional distillation is a separation technique that relies on the differences in boiling points of the components in a mixture. The component with the lower boiling point vaporizes first and can be collected separately.

3. **Liquefying Air**:
- To begin the process, air is first cooled and liquefied. This involves compressing the air and then allowing it to expand, which cools it down to very low temperatures.

4. **Boiling Points of Components**:
- The boiling points of the main components of air are:
- Nitrogen: 77 K
- Argon: 87.4 K
- Oxygen: 90 K
- From this, we can see that nitrogen has the lowest boiling point, followed by argon, and then oxygen.

5. **Separation Process**:
- In the fractional distillation column, as the liquefied air is gradually warmed, nitrogen will boil off first due to its lower boiling point. It is collected as it vaporizes.
- Next, argon will boil off and can be collected.
- Finally, oxygen, which has the highest boiling point among the three, will be collected last.

6. **Conclusion**:
- Therefore, it is possible to obtain oxygen from air by fractional distillation because oxygen has a higher boiling point than nitrogen, allowing for its separation after nitrogen has been removed.

### Final Answer:
Oxygen can be obtained from air by fractional distillation because oxygen has a higher boiling point than nitrogen.

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