Topic 2: First Law of Thermodynamics Flashcards
(13 cards)
formula for internal energy for ideal gas
U = U(0) + Uk(trans) + Uk(rot)
formula for internal energy of ideal gas molecules
monatomic: U = U(0) + 3/2nRT
diatomic or linear polyatomic: U = U(0) + 5/2nRT
nonlinear polyatomic: U = U(0) + 3nRT
what is the first law of thermodynamics
delta U = q + w
what are the state functions
U, P, V, T, H
what are the path functions
q , w
definition of adiabatic process
refers to energy exchange between system and surroundings through work only, q= 0
how to find q, w and delta U for isothermal reversible process
q = -w
w = -nRTln(Vf/Vi)
delta U = 0
how to find q, w and delta U for reversible adiabatic process
q = 0
w = delta U
delta U = nCvdeltaT
how to find q, w and delta U when volume is constant
q = delta U
w = 0
delta U = nCvdeltaT
how to find q, w and delta U when pressure is constant
q = delta H = nCpdeltaT
w = -PdeltaV
delta U = nCvdeltaT
how to find delta H at constant pressure
delta H = delta U + PdeltaV
OR
delta H = nCpdeltaT
how to find delta H at constant volume
delta H = delta U + nRdeltaT
