Question

A flask with open mouth containing air was heated from 27°C to 477°C. Some air was expelled. What is the fraction of air expelled out?

• A. $\frac{2}{5}$
• B. $\frac{1}{5}$
• C. $\frac{3}{5}$
• D. $\frac{4}{5}$

Hint:

For ideal gases, volume is proportional to temperature at constant pressure. So, calculate the change in temperature to find the change in volume.

Answer 1

The Correct Option is A

Since the flask is open and the air behaves ideally, we can use the combined gas law to find the fraction of air expelled. The fraction is given by the change in temperature, assuming ideal gas behavior.
For an ideal gas, the fraction of air expelled is \( \frac{T_2 - T_1}{T_2} \), where \( T_1 = 300 \, \text{K} \) and \( T_2 = 750 \, \text{K} \).
Thus, the fraction of air expelled is \( \frac{750 - 300}{750} = \frac{2}{5} \).