Week 2 Heat Capacity, JT effect and Second Law of Thermodynamics Flashcards
what is the general heat capacity eqn
Cx = dQ/dT –> dQ = CxdT
where x is some quantity such as volume or pressure that is fixed
what is the 1st Law volume heat capacity eqn for
dQ = CvdT = dE - dW
what is the 1st Law pressure heat capacity eqn
dQ = CpdT = dE + PdV
what two laws do Ideal gases obey
Boyle’s Law and Charles’ Law
define Boyles law
PV = const at fixed T
define Charles law
at constant P the Volume of a gas varies linearly with Temp
what are the two ideal gas eqn
PV = nRT = NkT
what is true of ideal gases that is not true of real gases
ideals energy is only dependent upon temperature
define Adiabatic
no heat transfer (dQ = 0)
define heat capacity
quantity of energy required to raise the temperature of one unit mass by one degree of temperature with a constant X property
what is the enthalpy eqn
H = E + PV
what does the JT (Joule Thomson) coefficient do and what is true of it
it defines cooling
μjt > 0 for cooling
define the JT effect
thermodynamic process that occurs in fluids when expanding from high pressure to low pressure at constant enthalpy
define the second law of thermodynamics
heat naturally flows from hot bodies to cold ones. To reverse that flow special conditions are required
what does the 2nd law of thermodynamics imply
entropy (S) can never decrease. Sf > Si for a irreversible process and Sf >= Si for a reversible one
