Step 1: Use the ideal gas law
The ideal gas law is:
\[
PV = nRT
\]
where:
- \( P \) is the pressure (in atm),
- \( V \) is the volume (in liters),
- \( n \) is the number of moles of gas,
- \( R \) is the ideal gas constant (\( 0.0821 \, \text{L} \cdot \text{atm} / \text{mol} \cdot \text{K} \)),
- \( T \) is the temperature (in Kelvin).
Step 2: Substitute the given values
Given:
- Pressure \( P = 2 \, \text{atm} \),
- Volume \( V = 5 \, \text{L} \),
- Temperature \( T = 300 \, \text{K} \),
- \( R = 0.0821 \, \text{L} \cdot \text{atm} / \text{mol} \cdot \text{K} \).
Now, solve for \( n \):
\[
n = \frac{PV}{RT}
\]
Substitute the known values:
\[
n = \frac{(2 \, \text{atm}) \times (5 \, \text{L})}{(0.0821 \, \text{L} \cdot \text{atm} / \text{mol} \cdot \text{K}) \times (300 \, \text{K})}
\]
\[
n = \frac{10}{24.63} = 0.406 \, \text{mol}
\]
Answer: Therefore, the total number of moles of gas in the container is approximately \( 0.4 \, \text{mol} \). So, the correct answer is option (1).