The First Law Flashcards
What is a Quasistatic process?
System remains in equilibrium.
Slow enough for system to respond (equilibrate).
Work on a system…
Increases energy
Work by a system…
Decreases energy
(Molecular interpretation) What is heat?
Transfer by disorderly molecular motion in surroundings.
HEAT CARRIES ENTROPY
(Molecular interpretation) What is work?
Transfer by orderly molecular motion in surroundings
(Molecular interpretation) What is thermal motion?
Random motion of particles
What is the First Law?
DeltaU = q + w
q = heat transferred to system w = work done on system
No change in U occurs when?
Isolated system
What is an open system?
Matter and energy transferred
What is a closed system?
No matter but energy is transferred
What is an isolated system?
No matter nor energy transferred
What is an adiabatic system?
Matter but no energy as heat is tranferred
What is a reversible process for adiabatic system?
System can be brought back to initial state
What is a reversible process for non-adiabatic system?
System can be brought back to initial state with no overall effect on surroundings
How do you achieve reversibility via a quasistatic process?
Change is gradual enough so system stays in equilibrium
