3.4 Thermodynamic Processes

When a gas expands isothermally, it does work. What is the source of energy needed to do this work?

It is unlikely that a process can be isothermal unless it is a very slow process. Explain why. Is the same true for isobaric and isochoric processes? Explain your answer.

Consider a transformation from point A to B in a two-step process. First, the pressure is lowered from 3 MPa at point A to a pressure of 1 MPa, while keeping the volume at 2 L by cooling the system. The state reached is labeled C. Then the system is heated at a constant pressure to reach a volume of 6 L in the state B. (a) Find the amount of work done on the ACB path. (b) Find the amount of heat e…

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…