termodinamica
2 kmol de hidrógeno por kmol de nitrógeno. El hidrógeno entra a 0.5 MPa, 20°C y
el nitrógeno entra a 0.5 MPa,200°C. La presión después de la mezcla es 0.49 MPa.
Determine la temperatura de la mezcla y el cambio neto de entropía por kmol de
mezcla.
Mezcla
Pm :=
0.49
TM :=
Estado 2H2
Estado 1H2NH2 :=
NN2 :=
Estado 2 N2
Estado 1N2
2
1
Propiedades :
P1H2 :=
0.5
P1N2 :=
0.5
T1H2 :=
20 + 273
T1N2 :=
200 + 273
CpN2m :=
Primera ley
1.045
MMN2 :=NH2⋅ h1H2 + NN2⋅ h1N2 = NH2⋅ h2H2 + NN2⋅ h2N2
CpH2m :=
MMH2 :=
28
kJ
kgK
14.4
2
CpN2 := CpN2m ⋅ MMN2
CpN2 =
kJ
kmolK
29.26
0 = NH2⋅ ( h2H2 − h1H2) + NN2⋅ ( h2N2 −h1N2)
CpH2 := CpH2m ⋅ MMH2
0 = NH2⋅ CpH2⋅ ( T2 − T1H2) + NN2⋅ CpN2⋅ ( T2 − T1N2)
CpH2 =
T2 :=
T2 =
28.8
NH2⋅ CpH2⋅ T1H2 + NN2⋅ CpN2⋅ T1N2
NH2⋅ CpH2 + NN2⋅ CpN2
kJ
kmolK
353.636másica
ΔStotal = ΔSH2 + ΔSN2 = mH2⋅ ( sm2H2 − sm1H2) + mN2⋅ ( sm2N2 − sm1N2)
sm2N2
ΔStotal = ΔSH2 + ΔSN2 = mH2⋅ ⎛CpH2m ⋅ ln⎛
⎜
⎜
T2 ⎞
⎟
⎝ T1H2 ⎠
⎝
− RH2⋅ ln⎛
⎜
P2H2 ⎞⎞
⎟⎟
⎝P1H2 ⎠⎠
+ mN2⋅ ⎛CpN2m ⋅ ln⎛
⎜
⎜
T2 ⎞
⎟
⎝ T1N2 ⎠
⎝
− RN2⋅ ln⎛
⎜
P2N2 ⎞⎞
⎟⎟
⎝ P1N2 ⎠⎠
molar
ΔStotal = ΔSH2 + ΔSN2 = NH2⋅ ( s2H2 − s1H2) + NN2⋅ ( s2N2 − s1N2)
s2N2
ΔStotal= ΔSH2 + ΔSN2 = NH2⋅ ⎛CpH2⋅ ln⎛
⎜
⎜
⎝
T2 ⎞
⎟
⎝ T1H2 ⎠
Pm = P2N2 + P2H2
− Ru ⋅ ln⎛
⎜
P2H2 ⎞⎞
⎟⎟
⎝ P1H2 ⎠⎠
kJoule
kgK
+ NN2⋅ ⎛CpN2⋅ ln⎛
⎜
⎜
⎝
T2 ⎞
⎟
⎝ T1N2 ⎠
−Ru ⋅ ln⎛
⎜
P2N2 ⎞⎞
⎟⎟
⎝ P1N2 ⎠⎠
kJoule
kmolK
T2 =
P2N2⋅ Vm
Ru ⋅ NN2
T2 =
P2N2
P2H2
=
NN2
NH2
P2H2⋅ Vm
Ru ⋅ NH2
NH2
=
NN2
P2N2 :=
Pm
3
P2N2 =
0.163P2H2 :=
2 ⋅ P2N2
P2H2 =
0.327
P2N2 + P2H2 =
Ru :=
8.314
ΔStotal := NH2⋅ ⎛CpH2⋅ ln⎛
⎜
⎜
⎝
ΔStotal =
18.704
0.49
T2 ⎞
⎟
⎝ T1H2 ⎠
− Ru ⋅ ln⎛
⎜
P2H2 ⎞⎞...
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