B.4 Thermodynamics (HL) Flashcards
Internal Energy (U)
Total energy contained by a system’s particles due to their motion and position
Work Done (W)
Energy transferred to or from a system when a force moves an object through a distance
ΔU in Ideal Gas
Change in internal energy of an ideal gas depends on the number of particles and temperature change
PV Diagram
Graph showing the relationship between a system’s pressure (P) and volume (V), where work done is the area under the curve
First Law of Thermodynamics
Energy within a closed system is conserved: ΔU = Q - W
Q = ΔU + W
Heat added to a system equals the change in internal energy plus the work done by the system
Closed System
A system that exchanges energy but not matter with its surroundings
Adiabatic Process
A thermodynamic process with no heat exchange with the surroundings
Isothermal Process
Process at constant temperature, implying ΔU = 0 for an ideal gas
Isochoric Process
Process at constant volume, meaning no work is done (W = 0)
Entropy (S)
Measure of disorder or randomness in a system, related to the number of possible microstates
Second Law of Thermodynamics
Total entropy of an isolated system can never decrease over time.
Microstates (Ω)
The number of possible configurations that a system can have
ΔS = ΔQ/T
Change in entropy is the heat added to the system divided by the temperature
Entropy and Isolated Systems
Entropy of an isolated system not in equilibrium almost always increases
