- #1
Philethan
- 35
- 4
Hello, every one! I'm studying the Section 9.2 - Phase Equilibrium of "Classical and Statistical Thermodynamics" written by Carter.
In equation (9.21) and (9.22)
He said:
[itex]dS_{A}=\frac{1}{T_{A}}(dU_{A}+P_{A}dV_{A}-\mu _{A}dn_{A})[/itex]-----(9.21)
[itex]dS_{B}=\frac{1}{T_{B}}(dU_{B}+P_{B}dV_{B}-\mu _{B}dn_{B})[/itex]-----(9.22)
I think dS and differentials of all other state variables should be zero! That is, dSA=dSB=dnA=dnB=dVA=dVB=...=0
Is it correct? If it's correct, then I cannot get the following conclusions which needs to assume those increments dUA,dVA,dnA,... could be arbitrary.
TA = TB (thermal equilibrium)
PA = PB (mechanical equilibrium)
μA = μB (diffusive equilibrium)
Thanks in advance!
In equation (9.21) and (9.22)
He said:
[itex]dS_{A}=\frac{1}{T_{A}}(dU_{A}+P_{A}dV_{A}-\mu _{A}dn_{A})[/itex]-----(9.21)
[itex]dS_{B}=\frac{1}{T_{B}}(dU_{B}+P_{B}dV_{B}-\mu _{B}dn_{B})[/itex]-----(9.22)
I think dS and differentials of all other state variables should be zero! That is, dSA=dSB=dnA=dnB=dVA=dVB=...=0
Is it correct? If it's correct, then I cannot get the following conclusions which needs to assume those increments dUA,dVA,dnA,... could be arbitrary.
TA = TB (thermal equilibrium)
PA = PB (mechanical equilibrium)
μA = μB (diffusive equilibrium)
Thanks in advance!