67 An ideal monatomic gas initially has a temperature of 330 K and a pressure of 6.00 atm. It is to expand from volume 500 cm3 to volume 1500 cm3. If the expansion is isothermal, what are (a) the final pressure and (b) the work done by the gas? If, instead, the ex- pansion is adiabatic, what are (c) the final pressure and (d) the work done by the gas