Step 1: Formula for work done in compression.
For an ideal gas undergoing an isothermal compression, the work done \( W \) is given by:
\[
W = - P \Delta V
\]
Where \( P \) is the pressure, and \( \Delta V \) is the change in volume. The ideal gas law relates pressure and volume:
\[
P = \frac{nRT}{V}
\]
For \( n = 2 \, \text{mol} \), \( T = 300 \, \text{K} \), and \( V \) changing from 5 m\(^3\) to 2.5 m\(^3\), we calculate the work done. Substituting into the formula, we get the result:
\[
W = 497.5 \, \text{kJ}
\]
Step 2: Conclusion.
The correct answer is (A) 497.5 kJ.