1.55 moles of Argon gas undergo an isothermal reversible expansion from an initial volume of 5.00 L to 105. L at 300 K. Calculate the work done during this process using: (a) the ideal gas equation, and (b) the van der Waals equation of state. Compare the two results, what percentage of the work done by the van der Waals gas arises due to having to overcome the attractive potential?