A flexible balloon contains 0.355 of an unknown polyatomic gas. Initially the balloon containing the gas has a volume of 6500 and a temperature of 30.0. The gas first expands isobarically until the volume doubles. Then it expands adiabatically until the temperature returns to its initial value. Assume that the gas may be treated as an ideal gas with Cp= 33 J/mol K and 4/3.