The work performed by a gas during an isobaric expansion (constant pressure) is calculated as:
\[
W = P \Delta V
\]
Given:
- Pressure, \( P = 2 \times 10^5 \, \text{Pa} \)
- Change in volume, \( \Delta V = V_f - V_i = 5 - 2 = 3 \, \text{m}^3 \)
Calculation:
\[
W = 2 \times 10^5 \times 3 = 6 \times 10^5 \, \text{J}
\]
The work done by the gas is \( 6 \times 10^5 \, \text{J} \).