Derive an expression for work done in reversible isothermal expansion of a gas obeying van der waals equation. calculate the work done in isotherfmal expansion of 1.0 mol of CO2 from an initial volume of 1 L to a final volume of 5.0 L assuming it an ideal gas and a van der Waals gas at a temprature 0f 300K. Van der Waals coefficients for CO2 are a=3.610 atm dm^6 mol^-2 and b=0.0429 dm^3 mol^-1?