3.2

Front: How is the infinitesimal work ( $dW$ ) done by a gas during a volume change defined?
Back: $dW = p \, dV$ , where $p$ is pressure and $dV$ is the change in volume.
Front: What is the formula for the net work ( $W$ ) done by a system during a finite volume change?
Back: $W = \int_{V_1}^{V_2} p \, dV$ .
Front: What is a quasi-static process?
Back: A process that occurs in infinitesimally small steps, keeping the system in thermal equilibrium.
Front: On a $pV$ diagram, what represents the work done by a gas?
Back: The area under the curve of the $pV$ graph.
Front: Is the work done by a system path-dependent or path-independent?
Back: Work is path-dependent; different thermodynamic paths between two states result in different amounts of work.
Front: What is the sign of work ( $W$ ) when a gas expands?
Back: Positive ( $W > 0$ ).
Front: What is the sign of work ( $W$ ) when a gas is compressed?
Back: Negative ( $W < 0$ ).
Front: How much work is done during a constant-volume (isochoric) process?
Back: Zero, because $dV = 0$ .

Front: What is the definition of internal energy ( $E_{int}$ )?
Back: The sum of the mechanical energies (kinetic and potential) of all molecules or entities within the system.
Front: What types of energy contribute to the internal energy of a molecule?
Back: Translational, rotational, and vibrational kinetic energy, plus potential energy from interatomic interactions.
Front: For an ideal monatomic gas, what constitutes the internal energy?
Back: Only translational kinetic energy, as there are no rotational/vibrational components or interatomic interactions.
Front: What is the formula for the internal energy ( $E_{int}$ ) of $n$ moles of an ideal monatomic gas?
Back: $E_{int} = \frac{3}{2} nRT$ .
Front: Does the internal energy of an ideal monatomic gas depend on pressure or volume?
Back: No, it depends strictly on the temperature.