laws of thermodynamic Flashcards
The first law of thermodynamics
ΔU = Q - W
where Q is the net heat added
W is the net work done by the system
ΔU is the change in internal energy of a closed system.
The first law of thermodynamics is also known as
the law of conservation of energy
work and heat are involved in thermodynamic processes can change
the internal energy of a closed system, that is ΔU.
What are the state variables?
internal energy U, Pressure P, Volume V, Temperature T, mass m, the number of moles n.
The First Law of Thermodynamics Extended
Δke + Δpe + ΔU = Q - W. (ke: kinetic energy, pe: potential energy).
Isothermal Processes
ΔT=0
Adiabatic Processes
Q=0 (đoạn nhiệt)
Isobaric and Isovolumetric Processes
ΔP= 0 and ΔV=0
the second law of thermodynamics
heat can flow spontaneously from a hot object to a cold object; heat will not
flow spontaneously from a cold object to a hot object.
heat engine
device that
changes thermal energy into mechanical work
Entropy
ΔS=Q/T
the second law of thermodynamics in term of entropy use
The entropy of an isolated system never decreases.
It can only stay the same or increase.
