3.4 Exercise 9

Two moles of helium gas are placed in a cylindrical container with a piston. The gas is at room temperature $25 ° \text{C}$ and under a pressure of $3.0 \times 10^{5} \text{Pa} .$ When the pressure from the outside is decreased while keeping the temperature the same as the room temperature, the volume of the gas doubles. (a) Find the work the external agent does on the gas in the process. (b) Find the heat exchanged by the gas and indicate whether the gas takes in or gives up heat. Assume ideal gas behavior.