1st Law Of Thermodynamics Flashcards
(20 cards)
What is the value of q in a reversible isothermal process?
q = -w = nRT ln(Vf/Vi)
What is the value of q in an irreversible isothermal process?
q = -w = PextΔV
What is the value of ΔH in an irreversible isothermal process?
0
What is the value of ΔH in a reversible isothermal process?
0
What is the value of ΔU in an irreversible isothermal process?
0
What is the value of ΔU in a reversible isothermal process?
0
What is the value of ΔH in an isobaric process?
ΔH = qp = nCpΔT
What is the value of work, w, in an isobaric process?
w = -PextΔV
What state function is heat equal to in an isobaric process?
ΔH, change in enthalpy
What is the value of work, w, in an isochoric process?
0
What is the value of heat, q, in an isochoric process?
q = qv = nCvΔT
What state function is equal to heat, q, in an isochoric process?
ΔU, change in internal energy
What is the value of ΔU in an isochoric process?
qv = nCvΔT
What is constant in an isobaric process?
P (bar in isobar = pressure)
What is constant in an isochoric process?
V, volume
What necessary condition consitutes a process to be adiabatic?
no heat flow, q = 0
What is the relationship between the molar heat capacities, Cp,m and Cv,m?
Cp,m - Cv,m = R
For monoatomic gases, what is the value of Cv,m?
3/2 R (3 degrees of freedom due to translational motion)
For diatomic gases, what is the value of Cv,m?
5/2 R (5 degrees of freedom: 3 - translational; 2 - rotational)
Where is the change in internal energy, ΔU, equal to in an adiabatic process?
ΔU = w
