HW #2: Cn 19 #'s 6 , 12 , 15 , 30 , 36 , 52 6 , 12 , 15 , 30 , 36 , 52 6,12,15,30,36,526,12,15,30,36,526,12,15,30,36,52
19-6) Ist law of TD tells us that the change in total internal energy of the system, Δ U = q + w Δ U = q + w Delta U=q+w\Delta U=q+wΔU=q+w
or that a small change d U = δ q + δ w d U = δ q + δ w dU=delta q+delta wd U=\delta q+\delta wdU=δq+δw where q > 0 q > 0 q > 0q>0q>0 : heat flows into the system
w>0: work done on the system
key to remember: ⋅ W ⋅ W *W\cdot W⋅W is minimiud when the prouss is reversible, ω m i n = ω rev ω m i n = ω rev  omega_(min)=omega_("rev "){\omega_{m i n}}=\omega_{\text {rev }}ωmin=ωrev 
  • For reverside procoses, P ext ≈ P int = n A T V P ext  ≈ P int  = n A T V P_("ext ")~~P_("int ")=(nAT)/(V)P_{\text {ext }} \approx P_{\text {int }}=\frac{n A T}{V}Pext ≈Pint =nATV so W evv = − ∫ V 1 V 2 P ext d V = − ∫ V 1 V 2 P int d V = − ∫ V 1 V 2 n A T V d V W evv  = − ∫ V 1 V 2   P ext  d V = − ∫ V 1 V 2   P int  d V = − ∫ V 1 V 2   n A T V d V W_("evv ")=-int_(V_(1))^(V_(2))P_("ext ")dV=-int_(V_(1))^(V_(2))P_("int ")dV=-int_(V_(1))^(V_(2))(nAT)/(V)dVW_{\text {evv }}=-\int_{V_{1}}^{V_{2}} P_{\text {ext }} d V=-\int_{V_{1}}^{V_{2}} P_{\text {int }} d V=-\int_{V_{1}}^{V_{2}} \frac{n A T}{V} d VWevv =−∫V1V2Pext dV=−∫V1V2Pint dV=−∫V1V2nATVdV
Isotherm: constant T T TTT
W reV = − ∫ V 1 V 2 P ext d V = − ∫ V 1 V 2 P int d V = − ∫ V 1 V 2 n R T V d V = − n R T ∫ V 1 V 2 1 V d V = − n R T ln ⁡ V | V 1 V 2 = − n R T ln ⁡ ( V 2 V 1 ) = n R T ln ⁡ ( V 1 V 2 ) W reV  = − ∫ V 1 V 2   P ext  d V = − ∫ V 1 V 2   P int  d V = − ∫ V 1 V 2   n R T V d V = − n R T ∫ V 1 V 2   1 V d V = − n R T ln ⁡ V V 1 V 2 = − n R T ln ⁡ V 2 V 1 = n R T ln ⁡ V 1 V 2 W_("reV ")=-int_(V_(1))^(V_(2))P_("ext ")dV=-int_(V_(1))^(V_(2))P_("int ")dV=-int_(V_(1))^(V_(2))(nRT)/(V)dV=-nRTint_(V_(1))^(V_(2))(1)/(V)dV=-nRT ln V|_(V_(1))^(V_(2))=-nRT ln((V_(2))/(V_(1)))=nRT ln((V_(1))/(V_(2)))W_{\text {reV }}=-\int_{V_{1}}^{V_{2}} P_{\text {ext }} d V=-\int_{V_{1}}^{V_{2}} P_{\text {int }} d V=-\int_{V_{1}}^{V_{2}} \frac{n R T}{V} d V=-n R T \int_{V_{1}}^{V_{2}} \frac{1}{V} d V=-\left.n R T \ln V\right|_{V_{1}} ^{V_{2}}=-n R T \ln \left(\frac{V_{2}}{V_{1}}\right)=n R T \ln \left(\frac{V_{1}}{V_{2}}\right)WreV =−∫V1V2Pext dV=−∫V1V2Pint dV=−∫V1V2nRTVdV=−nRT∫V1V21VdV=−nRTln⁡V|V1V2=−nRTln⁡(V2V1)=nRTln⁡(V1V2)
n = 5.00 n = 5.00 n=5.00n=5.00n=5.00 moles
T = 300 k T = 300 k T=300kT=300 \mathrm{k}T=300k
V 1 = 100.0 dm 3 V 2 = 40.0 dm 3 V 1 = 100.0 dm 3 V 2 = 40.0 dm 3 V_(1)=100.0dm^(3)quadV_(2)=40.0dm^(3)V_{1}=100.0 \mathrm{dm}^{3} \quad V_{2}=40.0 \mathrm{dm}^{3}V1=100.0dm3V2=40.0dm3
w min = w rev = − n ATln ( V 1 V 2 ) = − 5.00 cog ( 8.314 J sin ⁡ k ) ( 300 K ) ln ⁡ [ 40.0 dm d 8 100.00 dm 3 ] ⏟ = ln ⁡ ( 0.400 ) = + 11 , 400 J = 11.4 kJ w min  = w rev  = − n ATln V 1 V 2 = − 5.00 cog 8.314 J sin ⁡ k ( 300 K ) ln ⁡ 40.0 dm d 8 100.00 dm 3 ⏟ = ln ⁡ ( 0.400 ) = + 11 , 400 J = 11.4 kJ w_("min ")=w_("rev ")=-n ATln((V_(1))/(V_(2)))=-5.00 cog((8.314(J))/(sin k))(300K)ubrace(ln[(40.0dmd^(8))/(100.00dm^(3))]ubrace)_(=ln(0.400))=+11,400J=11.4kJw_{\text {min }}=w_{\text {rev }}=-n \operatorname{ATln}\left(\frac{V_{1}}{V_{2}}\right)=-5.00 \operatorname{cog}\left(\frac{8.314 \mathrm{~J}}{\sin k}\right)(300 \mathrm{~K}) \underbrace{\ln \left[\frac{40.0 \mathrm{dm} \mathrm{d}^{8}}{100.00 \mathrm{dm}^{3}}\right]}_{=\ln (0.400)}=+11,400 \mathrm{~J}=11.4 \mathrm{~kJ}wmin =wrev =−nATln(V1V2)=−5.00cog(8.314 Jsin⁡k)(300 K)ln⁡[40.0dmd8100.00dm3]⏟=ln⁡(0.400)=+11,400 J=11.4 kJ
Where there this comes from:
Our general desinition of Work is W = F ⋅ Δ h ′ W = F ⋅ Δ h ′ W=F*Deltah^(')W=F \cdot \Delta h^{\prime}W=F⋅Δh′, where W W WWW has units of N ⋅ m = J N ⋅ m = J N*m=JN \cdot m=JN⋅m=J, which are units of energy
  • use det P = F A ⇒ F = P A ⇒ W = P A ⋅ Δ h ⏟ Δ V = P Δ V P = F A ⇒ F = P A ⇒ W = P A ⋅ Δ h ⏟ Δ V = P Δ V P=(F)/(A)=>F=PA=>W=Pubrace(A*Delta hubrace)_(Delta V)=P Delta VP=\frac{F}{A} \Rightarrow F=P A \Rightarrow W=P \underbrace{A \cdot \Delta h}_{\Delta V}=P \Delta VP=FA⇒F=PA⇒W=PA⋅Δh⏟ΔV=PΔV
Explain neg.sign: define w > 0 w > 0 w > 0w>0w>0 as work done on gas
Compression: V 2 < V 1 − ∫ V 1 V 2 P ext d V = − P ext ( V 2 − V 1 ⏟ ( − ) ) = − ( − ) P ext Δ V = P ext Δ V , ↑ Δ U V 2 < V 1 − ∫ V 1 V 2   P ext  d V = − P ext  ( V 2 − V 1 ⏟ ( − ) ) = − ( − ) P ext  Δ V = P ext  Δ V , ↑ Δ U V_(2) < V_(1)-int_(V_(1))^(V_(2))P_("ext ")dV=-P_("ext ")(ubrace(V_(2)-V_(1)ubrace)_((-)))=-(-)P_("ext ")Delta V=P_("ext ")Delta V,quad uarr Delta UV_{2}<V_{1}-\int_{V_{1}}^{V_{2}} P_{\text {ext }} d V=-P_{\text {ext }}(\underbrace{V_{2}-V_{1}}_{(-)})=-(-) P_{\text {ext }} \Delta V=P_{\text {ext }} \Delta V, \quad \uparrow \Delta UV2<V1−∫V1V2Pext dV=−Pext (V2−V1⏟(−))=−(−)Pext ΔV=Pext ΔV,↑ΔU, work done on gas
Expansion: V 2 > V 1 − ∫ V 1 V 2 p ext d V = − p ext ( V 2 − V 1 ⏟ ( + ) ) = − p ext Δ V V 2 > V 1 − ∫ V 1 V 2   p ext  d V = − p ext  ( V 2 − V 1 ⏟ ( + ) ) = − p ext  Δ V V_(2) > V_(1)-int_(V_(1))^(V_(2))p_("ext ")dV=-p_("ext ")(ubrace(V_(2)-V_(1)ubrace)_((+)))=-p_("ext ")Delta VV_{2}>V_{1}-\int_{V_{1}}^{V_{2}} p_{\text {ext }} d V=-p_{\text {ext }}(\underbrace{V_{2}-V_{1}}_{(+)})=-p_{\text {ext }} \Delta VV2>V1−∫V1V2pext dV=−pext (V2−V1⏟(+))=−pext ΔV, ↓ Δ U ↓ Δ U darr Delta U\downarrow \Delta U↓ΔU, gus does work
19-12) P 1 = 2.00 bar P 2 = 4.00 bar P V = C = P 1 = 2.00 bar P 2 = 4.00 bar P V = C = quadP_(1)=2.00barquadP_(2)=4.00barquad(P)/(V)=C=\quad P_{1}=2.00 \mathrm{bar} \quad P_{2}=4.00 \mathrm{bar} \quad \frac{P}{V}=C=P1=2.00barP2=4.00barPV=C= constant * q q qqq and w w www are not state frns. Ther values are path-dependent
T 1 = 273 k T 2 = ? ⇒ P = V C V 1 = ? V 2 = ? C ¯ V = 12.5 J mol ⋅ h * reversibu, so w = − ∫ V 1 V 2 P ext d V = − ∫ V 1 V 2 P int d V , can use ideal ges law T 1 = 273 k      T 2 = ?      ⇒ P = V C V 1 = ?      V 2 = ?      C ¯ V = 12.5 J mol ⋅ h  * reversibu, so  w = − ∫ V 1 V 2   P ext  d V = − ∫ V 1 V 2   P int  d V , can use ideal ges law  {:[T_(1)=273k,T_(2)=?,=>P=VC],[V_(1)=?,V_(2)=?, bar(C)_(V)=12.5((J))/((mol)*(h))]:}quad" * reversibu, so "w=-int_(V_(1))^(V_(2))P_("ext ")dV=-int_(V_(1))^(V_(2))P_("int ")dV", can use ideal ges law "\begin{array}{lll} T_{1}=273 \mathrm{k} & T_{2}=? & \Rightarrow P=V C \\ V_{1}=? & V_{2}=? & \bar{C}_{V}=12.5 \frac{\mathrm{~J}}{\mathrm{~mol} \cdot \mathrm{~h}} \end{array} \quad \text { * reversibu, so } w=-\int_{V_{1}}^{V_{2}} P_{\text {ext }} d V=-\int_{V_{1}}^{V_{2}} P_{\text {int }} d V \text {, can use ideal ges law }T1=273kT2=?⇒P=VCV1=?V2=?C¯V=12.5 J mol⋅ h * reversibu, so w=−∫V1V2Pext dV=−∫V1V2Pint dV, can use ideal ges law 
Using ideal gas law, can find V 1 , V 2 , T 2 V 1 , V 2 , T 2 V_(1),V_(2),T_(2)V_{1}, V_{2}, T_{2}V1,V2,T2, and C C CCC : P V = n R T P V = n R T quad PV=nRT\quad P V=n R TPV=nRT
V 1 = n R T 1 P 1 = 1.00 mol ( 8.314 J ) ( 273 K ) 2.00 bar ⋅ 1 bar ⋅ m ⋅ s 2 10 5 kg ⋅ kg ⋅ m 1.5 ⋅ s 2 = 0.0113 m 2 1.00 bar = 10 5 Pa = 10 5 kg m ⋅ s 2 1.005 = 1.00 kg ⋅ m s 2 V 1 = n R T 1 P 1 = 1.00 mol ( 8.314 J ) ( 273 K ) 2.00 bar ⋅ 1 bar ⋅ m ⋅ s 2 10 5 kg ⋅ kg ⋅ m 1.5 ⋅ s 2 = 0.0113 m 2      1.00 bar = 10 5 Pa = 10 5 kg m ⋅ s 2      1.005 = 1.00 kg ⋅ m s 2 {:[V_(1)=(nRT_(1))/(P_(1))=1.00mol((8.314(J))(273(K)))/(2.00bar)*(1bar*(m)*s^(2))/(10^(5)(kg))*((kg)*(m))/(1.5*s^(2))=0.0113m^(2),1.00bar=10^(5)Pa=10^(5)kg],[m*s^(2),1.005=1.00((kg)*(m))/(s^(2))]:}\begin{array}{ll} V_{1}=\frac{n R T_{1}}{P_{1}}=1.00 \mathrm{~mol} \frac{(8.314 \mathrm{~J})(273 \mathrm{~K})}{2.00 \mathrm{bar}} \cdot \frac{1 \mathrm{bar} \cdot \mathrm{~m} \cdot \mathrm{~s}^{2}}{10^{5} \mathrm{~kg}} \cdot \frac{\mathrm{~kg} \cdot \mathrm{~m}}{1.5 \cdot \mathrm{~s}^{2}}=0.0113 \mathrm{~m}^{2} & 1.00 \mathrm{bar}=10^{5} \mathrm{~Pa}=10^{5} \mathrm{~kg} \\ \mathrm{~m} \cdot \mathrm{~s}^{2} & 1.005=1.00 \frac{\mathrm{~kg} \cdot \mathrm{~m}}{\mathrm{~s}^{2}} \end{array}V1=nRT1P1=1.00 mol(8.314 J)(273 K)2.00bar⋅1bar⋅ m⋅ s2105 kg⋅ kg⋅ m1.5⋅ s2=0.0113 m21.00bar=105 Pa=105 kg m⋅ s21.005=1.00 kg⋅ m s2
P 1 V 1 = C = 2.00 bor 0.0113 m 2 ⋅ 10 5 kg 1 bar ⋅ m 2 = 1.762 × 10 7 kg m 3 ⋅ s 2 P 1 V 1 = C = 2.00 bor 0.0113 m 2 ⋅ 10 5 kg 1 bar ⋅ m 2 = 1.762 × 10 7 kg m 3 ⋅ s 2 (P_(1))/(V_(1))=C=(2.00bor)/(0.0113m^(2))*(10^(5)(kg))/(1bar*m^(2))=1.762 xx10^(7)((kg))/(m^(3)*s^(2))\frac{P_{1}}{V_{1}}=C=\frac{2.00 \mathrm{bor}}{0.0113 \mathrm{~m}^{2}} \cdot \frac{10^{5} \mathrm{~kg}}{1 \mathrm{bar} \cdot \mathrm{m}^{2}}=1.762 \times 10^{7} \frac{\mathrm{~kg}}{\mathrm{~m}^{3} \cdot \mathrm{~s}^{2}}P1V1=C=2.00bor0.0113 m2⋅105 kg1bar⋅m2=1.762×107 kg m3⋅ s2
V 2 = P 2 C = 4.00 bat − m 2 ⋅ s 2 1.762 + 10 7 kg ⋅ 10 5 kg 1.00 bar ⋅ gr ⋅ g 2 = 0.0226 m 2 V 2 = P 2 C = 4.00 bat − m 2 ⋅ s 2 1.762 + 10 7 kg ⋅ 10 5 kg 1.00 bar ⋅ gr ⋅ g 2 = 0.0226 m 2 V_(2)=(P_(2))/(C)=(4.00bat-m^(2)*s^(2))/(1.762+10^(7)(kg))*(10^(5)(kg))/(1.00bar*gr*g^(2))=0.0226m^(2)V_{2}=\frac{P_{2}}{C}=\frac{4.00 \mathrm{bat}-\mathrm{m}^{2} \cdot \mathrm{~s}^{2}}{1.762+10^{7} \mathrm{~kg}} \cdot \frac{10^{5} \mathrm{~kg}}{1.00 \mathrm{bar} \cdot \mathrm{gr} \cdot \mathrm{g}^{2}}=0.0226 \mathrm{~m}^{2}V2=P2C=4.00bat−m2⋅ s21.762+107 kg⋅105 kg1.00bar⋅gr⋅g2=0.0226 m2
T 2 = P 2 V 2 n R = 4.00 bark ( 0.0226 m 2 ) mot ⋅ k ⋅ 10 5 kg 16 ar ⋅ gr 2 1.00 mc ⋅ 8.314 z ⋅ 1 J ⋅ s 2 Kgm = 1092 K T 2 = P 2 V 2 n R = 4.00 bark 0.0226 m 2 mot ⋅ k ⋅ 10 5 kg 16 ar ⋅ gr 2 1.00 mc ⋅ 8.314 z ⋅ 1 J ⋅ s 2 Kgm = 1092 K T_(2)=(P_(2)V_(2))/(nR)=(4.00bark(0.0226m^(2))mot*k*(10^(5)(kg))/(16ar*gr^(2)))/(1.00mc*8.314z)*(1(J)*s^(2))/(Kgm)=1092KT_{2}=\frac{P_{2} V_{2}}{n R}=\frac{4.00 \mathrm{bark}\left(0.0226 \mathrm{~m}^{2}\right) \mathrm{mot} \cdot \mathrm{k} \cdot \frac{10^{5} \mathrm{~kg}}{16 \mathrm{ar} \cdot \mathrm{gr}^{2}}}{1.00 \mathrm{mc} \cdot 8.314 \mathrm{z}} \cdot \frac{1 \mathrm{~J} \cdot \mathrm{~s}^{2}}{\mathrm{Kgm}}=1092 \mathrm{~K}T2=P2V2nR=4.00bark(0.0226 m2)mot⋅k⋅105 kg16ar⋅gr21.00mc⋅8.314z⋅1 J⋅ s2Kgm=1092 K
Δ U = n ∫ T 1 T 2 C V ― d T = n C ¯ V T | T 1 T 2 n C ¯ V ( T 2 − T 1 ) = 1.00 mol ( 12.5 J J / K ) ( 1092 K − 273 K ) = 10 , 200 J = 10.2 kJ ( C V = n C V ― ) Δ U = n ∫ T 1 T 2   C V ¯ d T = n C ¯ V T T 1 T 2 n C ¯ V T 2 − T 1 = 1.00 mol ( 12.5 J J / K ) ( 1092 K − 273 K ) = 10 , 200 J = 10.2 kJ C V = n C V ¯ Delta U=nint_(T_(1))^(T_(2)) bar(C_(V))dT=n bar(C)_(V)T|_(T_(1))^(T_(2))n bar(C)_(V)(T_(2)-T_(1))=1.00mol(12.5JJ//K)(1092K-273K)=10,200J=10.2kJquad(C_(V)=n bar(C_(V)))\Delta U=n \int_{T_{1}}^{T_{2}} \overline{C_{V}} d T=\left.n \bar{C}_{V} T\right|_{T_{1}} ^{T_{2}} n \bar{C}_{V}\left(T_{2}-T_{1}\right)=1.00 \mathrm{~mol}(12.5 \mathrm{~J} \mathrm{~J} / \mathrm{K})(1092 \mathrm{~K}-273 \mathrm{~K})=10,200 \mathrm{~J}=10.2 \mathrm{~kJ} \quad\left(C_{V}=n \overline{C_{V}}\right)ΔU=n∫T1T2CV―dT=nC¯VT|T1T2nC¯V(T2−T1)=1.00 mol(12.5 J J/K)(1092 K−273 K)=10,200 J=10.2 kJ(CV=nCV―)
w = − ∫ V 1 V 2 p ext d V = − ∫ V 1 V 2 p int d V = − ∑ V 1 V 2 C V ⏟ sub p int = C V d V = − C V 2 2 | V 1 V 2 = − C 2 ( V 2 2 − V 1 2 ) = − 1.762 × 10 2 kg m 3 ⋅ s 2 2 ( ( 0.0226 m 2 ) 2 − ( 0.0113 m 2 ) 2 ) = w = − ∫ V 1 V 2   p ext  d V = − ∫ V 1 V 2   p int  d V = − ∑ V 1 V 2   C V ⏟ sub  p int  = C V d V = − C V 2 2 V 1 V 2 = − C 2 V 2 2 − V 1 2 = − 1.762 × 10 2 kg m 3 ⋅ s 2 2 0.0226 m 2 2 − 0.0113 m 2 2 = w=-int_(V_(1))^(V_(2))p_("ext ")dV=-int_(V_(1))^(V_(2))p_("int ")dV=-sum_(V_(1))^(V_(2))ubrace(CVubrace)_("sub "p_("int ")=CV)dV=-(CV^(2))/(2)|_(V_(1))^(V_(2))=(-C)/(2)(V_(2)^(2)-V_(1)^(2))=(-1.762 xx10^(2)((kg))/(m^(3)*s^(2)))/(2)((0.0226m^(2))^(2)-(0.0113m^(2))^(2))=w=-\int_{V_{1}}^{V_{2}} p_{\text {ext }} d V=-\int_{V_{1}}^{V_{2}} p_{\text {int }} d V=-\sum_{V_{1}}^{V_{2}} \underbrace{C V}_{\text {sub } p_{\text {int }}=C V} d V=-\left.\frac{C V^{2}}{2}\right|_{V_{1}} ^{V_{2}}=\frac{-C}{2}\left(V_{2}^{2}-V_{1}^{2}\right)=\frac{-1.762 \times 10^{2} \frac{\mathrm{~kg}}{\mathrm{~m}^{3} \cdot \mathrm{~s}^{2}}}{2}\left(\left(0.0226 \mathrm{~m}^{2}\right)^{2}-\left(0.0113 \mathrm{~m}^{2}\right)^{2}\right)=w=−∫V1V2pext dV=−∫V1V2pint dV=−∑V1V2CV⏟sub pint =CVdV=−CV22|V1V2=−C2(V22−V12)=−1.762×102 kg m3⋅ s22((0.0226 m2)2−(0.0113 m2)2)=
= − 3 , 374.8 J ≈ − 3 , 400 J = − 3.40 kJ = − 3 , 374.8 J ≈ − 3 , 400 J = − 3.40 kJ =-3,374.8J~~-3,400J=-3.40kJ=-3,374.8 \mathrm{~J} \approx-3,400 \mathrm{~J}=-3.40 \mathrm{~kJ}=−3,374.8 J≈−3,400 J=−3.40 kJ
Δ U = q + w ⇒ q = Δ U − w = 10.2 kJ − ( − 3.40 kJ ) = 13.6 kJ Δ U = q + w ⇒ q = Δ U − w = 10.2 kJ − ( − 3.40 kJ ) = 13.6 kJ Delta U=q+w=>q=Delta U-w=10.2kJ-(-3.40kJ)=13.6kJ\Delta U=q+w \Rightarrow q=\Delta U-w=10.2 \mathrm{~kJ}-(-3.40 \mathrm{~kJ})=13.6 \mathrm{~kJ}ΔU=q+w⇒q=ΔU−w=10.2 kJ−(−3.40 kJ)=13.6 kJ
Enthalpy is a quantity we define as: H = U + ⏟ s e + P V = H = U + ⏟ s e + P V = H=U+ubrace(ubrace)_(se+PV)=H=U+\underbrace{}_{s e+P V}=H=U+⏟se+PV= RAT
Δ H = Δ U + P Δ V + V Δ P = Δ U + nRAT ⏟ T easher to compute Δ H = Δ U + P Δ V + V Δ P = Δ U +  nRAT  ⏟ T easher to compute  Delta H=Delta U+P Delta V+V Delta P=ubrace(Delta U+" nRAT "ubrace)_(T_("easher to compute "))\Delta H=\Delta U+P \Delta V+V \Delta P=\underbrace{\Delta U+\text { nRAT }}_{T_{\text {easher to compute }}}ΔH=ΔU+PΔV+VΔP=ΔU+ nRAT ⏟Teasher to compute 
so Δ H = Δ U + Δ H = Δ U + Delta H=Delta U+\Delta H=\Delta U+ΔH=ΔU+ nR Δ T = 10.2 kJ + 1.00 mot ( 8.31 4 J K ⋅ 908 ) ( 1092 K − 273 K ) ⏟ 6 , 809.23 = 6.8 kJ = ( 10.2 + 6.8 ) kJ = 17.0 kJ Δ T = 10.2 kJ + 1.00 mot 8.31 4 J K ⋅ 908 ( 1092 K − 273 K ) ⏟ 6 , 809.23 = 6.8 kJ = ( 10.2 + 6.8 ) kJ = 17.0 kJ Delta T=10.2kJ+ubrace(1.00mot(8.31(4(J))/(K*908))(1092(K)-273(K))ubrace)_(6,809.23=6.8kJ)=(10.2+6.8)kJ=17.0kJ\Delta T=10.2 \mathrm{~kJ}+\underbrace{1.00 \mathrm{mot}\left(8.31 \frac{4 \mathrm{~J}}{K \cdot 908}\right)(1092 \mathrm{~K}-273 \mathrm{~K})}_{6,809.23=6.8 \mathrm{~kJ}}=(10.2+6.8) \mathrm{kJ}=17.0 \mathrm{~kJ}ΔT=10.2 kJ+1.00mot(8.314 JK⋅908)(1092 K−273 K)⏟6,809.23=6.8 kJ=(10.2+6.8)kJ=17.0 kJ
19-15) Show T 2 T 1 = ( V V 2 ) Λ C v ― T 2 T 1 = V V 2 Λ C v ¯ (T_(2))/(T_(1))=((V)/(V_(2)))^((Lambda)/( bar(C_(v))))\frac{T_{2}}{T_{1}}=\left(\frac{V}{V_{2}}\right)^{\frac{\Lambda}{\overline{C_{v}}}}T2T1=(VV2)ΛCv― for reversible adiabatic expansion of ideal gas
adiabatic: δ q = 0 δ q = 0 delta_(q)=0\delta_{q}=0δq=0
d U = δ ξ 0 + δ w = δ w ⇒ d U = δ w d U = δ ξ 0 + δ w = δ w ⇒ d U = δ w dU=deltaxi^(0)+delta w=delta w quad=>dU=delta wd U=\delta \xi^{0}+\delta w=\delta w \quad \Rightarrow d U=\delta wdU=δξ0+δw=δw⇒dU=δw
*want to rewrite d U d U dUd UdU and δ w δ w delta w\delta wδw, then work out a relationship:
We can write U (or any state function) as a total disserential:
U ( T , V ) ⇒ d U = ∂ U ∂ T ) V d T + ∂ U ∂ V | T d V U ( T , V ) ⇒ d U = ∂ U ∂ T V d T + ∂ U ∂ V T d V U(T,V)=>dU=(del U)/(del T))_(V)dT+(del U)/(del V)|_(T)dV quad\left.U(T, V) \Rightarrow d U=\frac{\partial U}{\partial T}\right)_{V} d T+\left.\frac{\partial U}{\partial V}\right|_{T} d V \quadU(T,V)⇒dU=∂U∂T)VdT+∂U∂V|TdV Use: d U = n C ¯ V d T d U = n C ¯ V d T dU=n bar(C)_(V)dT quadd U=n \bar{C}_{V} d T \quaddU=nC¯VdT Q w reV = − ∫ P ext d V = − ∫ int d V = − ∫ n R T V d V w reV  = − ∫ P ext    d V = − ∫ int    d V = − ∫ n R T V d V quadw_("reV ")=-int_(P_("ext "))dV=-int_("int ")dV=-int(nRT)/(V)dV\quad w_{\text {reV }}=-\int_{P_{\text {ext }}} d V=-\int_{\text {int }} d V=-\int \frac{n R T}{V} d VwreV =−∫Pext dV=−∫int dV=−∫nRTVdV
∂ U ∂ N ) T = 0 ∂ U ∂ N T = 0 (del U)/(del N))_(T)=0\left.\frac{\partial U}{\partial N}\right)_{T}=0∂U∂N)T=0 for ideal gas → → rarr\rightarrow→ asour Uonly changs w / T : U ¯ = 3 2 R T w / T : U ¯ = 3 2 R T w//T: bar(U)=(3)/(2)RTw / T: \bar{U}=\frac{3}{2} R Tw/T:U¯=32RT
(each D.O.F contriburs R T 2 R T 2 (RT)/(2)\frac{R T}{2}RT2 to U ¯ U ¯ bar(U)\bar{U}U¯ )
⇒ d U = δ ω reV P ext = P int for revesible work n C ¯ V d T = − P int d V ¯ sub P = n R T V ⇒ d U = δ ω reV       P ext  = P int for   revesible work  n C ¯ V d T = − P int  d V ¯       sub  P = n R T V {:[=>dU=deltaomega_("reV "),quadP_("ext ")=P_("int for ")" revesible work "],[n bar(C)_(V)dT=-P_("int ")d bar(V)," sub "P=(nRT)/(V)]:}\begin{array}{ll}\Rightarrow d U=\delta \omega_{\text {reV }} & \quad P_{\text {ext }}=P_{\text {int for }} \text { revesible work } \\ n \bar{C}_{V} d T=-P_{\text {int }} d \bar{V} & \text { sub } P=\frac{n R T}{V}\end{array}⇒dU=δωreV Pext =Pint for  revesible work nC¯VdT=−Pint dV¯ sub P=nRTV
A C ¯ d T = − Q R T V d V A C ¯ d T = − Q R T V d V A bar(C)dT=(-QRT)/(V)dVA \bar{C} d T=\frac{-Q R T}{V} d VAC¯dT=−QRTVdV reacrange
∫ T 1 T 2 C V ― d T T = ∫ V 1 V 2 − R V d V ∫ T 1 T 2   C V ¯ d T T = ∫ V 1 V 2   − R V d V int_(T_(1))^(T_(2))( bar(C_(V))dT)/(T)=int_(V_(1))^(V_(2))(-R)/(V)dV\int_{T_{1}}^{T_{2}} \frac{\overline{C_{V}} d T}{T}=\int_{V_{1}}^{V_{2}} \frac{-R}{V} d V∫T1T2CV―dTT=∫V1V2−RVdV Integrate B.S.
C V ― ln ⁡ T | T 1 T 2 = − R ln ⁡ V | V 1 V 2 C V ¯ ln ⁡ T T 1 T 2 = − R ln ⁡ V V 1 V 2 bar(C_(V))ln T|_(T_(1))^(T_(2))=-R ln V|_(V_(1))^(V_(2))\left.\overline{C_{V}} \ln T\right|_{T_{1}} ^{T_{2}}=-\left.R \ln V\right|_{V_{1}} ^{V_{2}}CV―ln⁡T|T1T2=−Rln⁡V|V1V2
C v ln ⁡ ( T 2 T 1 ) ― = − R ln ⁡ ( V 2 V 1 ) ^ C v ln ⁡ T 2 T 1 ¯ = − R ln ⁡ V 2 V 1 ^ bar(C_(v)ln((T_(2))/(T_(1))))=- widehat(R ln((V_(2))/(V_(1))))\overline{C_{v} \ln \left(\frac{T_{2}}{T_{1}}\right)}=-\widehat{R \ln \left(\frac{V_{2}}{V_{1}}\right)}Cvln⁡(T2T1)―=−Rln⁡(V2V1)^
e ln ⁡ ( T 2 T 1 ) V v ― = e ln ⁡ ( V 2 V 1 ) − R exponentiate B.S. e ln ⁡ T 2 T 1 V v ¯ = e ln ⁡ V 2 V 1 − R  exponentiate B.S.  e^(ln ((T_(2))/(T_(1)))^( bar(V_(v)))=e^(ln ((V_(2))/(V_(1)))^(-R))quad" exponentiate B.S. ")e^{\ln \left(\frac{T_{2}}{T_{1}}\right)^{\overline{V_{v}}}=e^{\ln \left(\frac{V_{2}}{V_{1}}\right)^{-R}} \quad \text { exponentiate B.S. }}eln⁡(T2T1)Vv―=eln⁡(V2V1)−R exponentiate B.S. 
( ( T 2 T 1 ) S 1 ― V 1 ) 1 V 1 = ( ( V 2 V 1 ) − R ) 1 V v raise B.S. to ( 1 C v ) ( T 2 T 1 ) = ( V 2 V 1 ) − 1 C v = ( V 1 V 2 ) h C v / T 2 T 1 S 1 ¯ V 1 1 V 1 = V 2 V 1 − R 1 V v  raise B.S. to  1 C v T 2 T 1 = V 2 V 1 − 1 C v = V 1 V 2 h C v / {:[(((T_(2))/(T_(1)))^(( bar(S_(1)))/(V_(1))))^((1)/(V_(1)))=(((V_(2))/(V_(1)))^(-R))^((1)/(V_(v)))quad" raise B.S. to "((1)/(C_(v)))],[((T_(2))/(T_(1)))=((V_(2))/(V_(1)))^((-1)/(C_(v)))=((V_(1))/(V_(2)))^((h)/(C_(v)))//]:}\begin{aligned} & \left(\left(\frac{T_{2}}{T_{1}}\right)^{\frac{\overline{S_{1}}}{V_{1}}}\right)^{\frac{1}{V_{1}}}=\left(\left(\frac{V_{2}}{V_{1}}\right)^{-R}\right)^{\frac{1}{V_{v}}} \quad \text { raise B.S. to }\left(\frac{1}{C_{v}}\right) \\ & \left(\frac{T_{2}}{T_{1}}\right)=\left(\frac{V_{2}}{V_{1}}\right)^{\frac{-1}{C_{v}}}=\left(\frac{V_{1}}{V_{2}}\right)^{\frac{h}{C_{v}}} / \end{aligned}((T2T1)S1―V1)1V1=((V2V1)−R)1Vv raise B.S. to (1Cv)(T2T1)=(V2V1)−1Cv=(V1V2)hCv/
sin ⁡ u ( V 2 V 1 ) − 1 = V 1 V 2 sin ⁡ u V 2 V 1 − 1 = V 1 V 2 sin u((V_(2))/(V_(1)))^(-1)=(V_(1))/(V_(2))\sin u\left(\frac{V_{2}}{V_{1}}\right)^{-1}=\frac{V_{1}}{V_{2}}sin⁡u(V2V1)−1=V1V2
19-30) Fur ideal gas: ( ∂ U ∂ V ) T = 0 ∂ U ∂ V T = 0 ((del U)/(del V))_(T)=0\left(\frac{\partial U}{\partial V}\right)_{T}=0(∂U∂V)T=0, prove ( ∂ H ∂ V ) T = 0 ∂ H ∂ V T = 0 ((del H)/(del V))_(T)=0\left(\frac{\partial H}{\partial V}\right)_{T}=0(∂H∂V)T=0
Recall H = U + P V = ideal gas law U + n R T H = U + P V =  ideal gas law  U + n R T H=U+PV=^(" ideal gas law ")U+nRTH=U+P V \stackrel{\text { ideal gas law }}{=} U+n R TH=U+PV= ideal gas law U+nRT
If keep H = U + P V H = U + P V H=U+PVH=U+P VH=U+PV, need to use product rule on ( ∂ ∂ V ( P V ) ) T ∂ ∂ V ( P V ) T ((del)/(del V)(PV))_(T)\left(\frac{\partial}{\partial V}(P V)\right)_{T}(∂∂V(PV))T :
( ∂ H ∂ V ) T = ( ∂ V ∂ V ) T 0 + n R ∂ n R T ∂ V ) T ⏟ = 0 since T is constant! ∂ H ∂ V T = ∂ V ∂ V T 0 + n R ∂ n R T ∂ V T ⏟ = 0  since  T  is constant!  {:[((del H)/(del V))_(T)=((del V)/(del V))_(T)^(0)+ubrace((nR)/((del nRT)/(del V)))_(T)ubrace)=0],[" since "T" is constant! "]:}\begin{gathered} \left(\frac{\partial H}{\partial V}\right)_{T}=\left(\frac{\partial V}{\partial V}\right)_{T}^{0}+\underbrace{\left.\frac{n R}{\frac{\partial n R T}{\partial V}}\right)_{T}}=0 \\ \text { since } T \text { is constant! } \end{gathered}(∂H∂V)T=(∂V∂V)T0+nR∂nRT∂V)T⏟=0 since T is constant! 
( ∂ H ∂ V ) T = ( ∂ U ∂ V ) T T 0 + V ( ∂ P ∂ V ) T + P ( ∂ V ∂ V ⏟ = 1 ) T ( ∂ H ∂ V ) T = V ( ∂ P ∂ V ) T + P ← sub P = n R T V ( ∂ H ∂ V ) T = V ( ∂ ∂ V n R T V ) T + n R T V = X ( − n R T V 2 ) + n R T V = − n R T V + n R T V = 0 ∂ H ∂ V T = ∂ U ∂ V T T 0 + V ∂ P ∂ V T + P ( ∂ V ∂ V ⏟ = 1 ) T ∂ H ∂ V T = V ∂ P ∂ V T + P ←  sub  P = n R T V ∂ H ∂ V T = V ∂ ∂ V n R T V T + n R T V = X − n R T V 2 + n R T V = − n R T V + n R T V = 0 {:[((del H)/(del V))_(T)=((del U)/(del V))_(T)^(T^(0))+V((del P)/(del V))_(T)+P(ubrace((del V)/(del V)ubrace)_(=1))_(T)],[((del H)/(del V))_(T)=V((del P)/(del V))_(T)+P larr" sub "P=(nRT)/(V)],[((del H)/(del V))_(T)=V((del)/(del V)(nRT)/(V))_(T)+(nRT)/(V)=X((-nRT)/(V^(2)))+(nRT)/(V)=(-nRT)/(V)+(nRT)/(V)=0]:}\begin{aligned} & \left(\frac{\partial H}{\partial V}\right)_{T}=\left(\frac{\partial U}{\partial V}\right)_{T}^{T^{0}}+V\left(\frac{\partial P}{\partial V}\right)_{T}+P(\underbrace{\frac{\partial V}{\partial V}}_{=1})_{T} \\ & \left(\frac{\partial H}{\partial V}\right)_{T}=V\left(\frac{\partial P}{\partial V}\right)_{T}+P \leftarrow \text { sub } P=\frac{n R T}{V} \\ & \left(\frac{\partial H}{\partial V}\right)_{T}=V\left(\frac{\partial}{\partial V} \frac{n R T}{V}\right)_{T}+\frac{n R T}{V}=X\left(\frac{-n R T}{V^{2}}\right)+\frac{n R T}{V}=\frac{-n R T}{V}+\frac{n R T}{V}=0 \end{aligned}(∂H∂V)T=(∂U∂V)TT0+V(∂P∂V)T+P(∂V∂V⏟=1)T(∂H∂V)T=V(∂P∂V)T+P← sub P=nRTV(∂H∂V)T=V(∂∂VnRTV)T+nRTV=X(−nRTV2)+nRTV=−nRTV+nRTV=0
19-36 Hess's Law
2 F 2 ( g ) + 2 H 2 O ( l ) ⟶ 4 HF ( g ) + O 2 ( g ) 2 F 2 ( g ) + 2 H 2 O ( l ) ⟶ 4 HF ( g ) + O 2 ( g ) 2F_(2)(g)+2H_(2)O(l)longrightarrow4HF(g)+O_(2)(g)2 \mathrm{~F}_{2}(\mathrm{~g})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \longrightarrow 4 \mathrm{HF}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g})2 F2( g)+2H2O(l)⟶4HF( g)+O2( g)
4 ( 1 2 H 2 ( g ) + 1 2 F 2 ( g ) ⟶ H F ( g ) ) 4 Δ r H ∘ = − 273.3 kJ / mol 4 1 2 H 2 ( g ) + 1 2 F 2 ( g ) ⟶ H F ( g ) 4 Δ r H ∘ = − 273.3 kJ / mol 4((1)/(2)H_(2)(g)+(1)/(2)F_(2)(g)longrightarrow HF(g))quad4Delta_(r)H^(@)=-273.3kJ//mol4\left(\frac{1}{2} H_{2}(g)+\frac{1}{2} F_{2}(g) \longrightarrow H F(g)\right) \quad 4 \Delta_{r} H^{\circ}=-273.3 \mathrm{~kJ} / \mathrm{mol}4(12H2(g)+12F2(g)⟶HF(g))4ΔrH∘=−273.3 kJ/mol
2 ( H 2 O ( l ) ⟶ 1 2 O 3 ( g ) + H 2 ( g ) ) 2 ( Δ r H ∘ = + 285.8 kJ / mol ) 2 H 2 O ( l ) ⟶ 1 2 O 3 ( g ) + H 2 ( g ) 2 Δ r H ∘ = + 285.8 kJ / mol 2(H_(2)O(l)longrightarrow(1)/(2)O_(3)((g))+H_(2)((g)))quad2(Delta_(r)H^(@)=+285.8(kJ)//mol)quad2\left(\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \longrightarrow \frac{1}{2} \mathrm{O}_{3}(\mathrm{~g})+\mathrm{H}_{2}(\mathrm{~g})\right) \quad 2\left(\Delta_{r} H^{\circ}=+285.8 \mathrm{~kJ} / \mathrm{mol}\right) \quad2(H2O(l)⟶12O3( g)+H2( g))2(ΔrH∘=+285.8 kJ/mol) (swap dicection)
↪ ↪ ↪\hookrightarrow↪
2 H 2 ( g ) + 2 F 2 ( g ) ⟶ 4 HF ( g ) 2 H 2 ( g ) + 2 F 2 ( g ) ⟶ 4 HF ( g ) 2H_(2)(g)+2F_(2)(g)longrightarrow4HF(g)2 \mathrm{H}_{2}(\mathrm{~g})+2 \mathrm{~F}_{2}(\mathrm{~g}) \longrightarrow 4 \mathrm{HF}(\mathrm{g})2H2( g)+2 F2( g)⟶4HF(g)
+ 2 H 2 O ( l ) ⟶ O 2 ( g ) + 2 H 2 ( g ) + 2 H 2 O ( l ) ⟶ O 2 ( g ) + 2 H 2 ( g ) +2H_(2)O(l)longrightarrowO_(2)(g)+2H_(2)(g)+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \longrightarrow \mathrm{O}_{2}(\mathrm{~g})+2 \mathrm{H}_{2}(\mathrm{~g})+2H2O(l)⟶O2( g)+2H2( g)
2 F 2 ( g ) + 2 H 2 O ( l ) ⟶ 4 HF ( g ) + O 2 ( g ) 2 F 2 ( g ) + 2 H 2 O ( l ) ⟶ 4 HF ( g ) + O 2 ( g ) 2F_(2)(g)+2H_(2)O(l)longrightarrow4HF(g)+O_(2)(g)2 \mathrm{~F}_{2}(\mathrm{~g})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \longrightarrow 4 \mathrm{HF}(\mathrm{g})+\mathrm{O}_{2}(\mathrm{~g})2 F2( g)+2H2O(l)⟶4HF(g)+O2( g)
Δ r H ∘ = 4 ( − 273.3 kJ / mol ) + 2 ( 285.8 kJ / mol ) = − 521.6 kJ Δ r H ∘ = 4 ( − 273.3 kJ / mol ) + 2 ( 285.8 kJ / mol ) = − 521.6 kJ Delta_(r)H^(@)=4(-273.3kJ//mol)+2(285.8kJ//mol)=-521.6kJ\Delta_{r} H^{\circ}=4(-273.3 \mathrm{~kJ} / \mathrm{mol})+2(285.8 \mathrm{~kJ} / \mathrm{mol})=-521.6 \mathrm{~kJ}ΔrH∘=4(−273.3 kJ/mol)+2(285.8 kJ/mol)=−521.6 kJ
19-52)
ω = P 1 V 1 − P 2 V 2 ⏟ (given) Ist law TD: q = 0 since no neat exchange w/ environment Δ v = U 2 − U 1 = λ 0 + ω 2 ω = P 1 V 1 − P 2 V 2 ⏟  (given)   Ist law TD:  q = 0  since no neat exchange w/ environment  Δ v = U 2 − U 1 = λ 0 + ω 2 {:[omega=ubrace(P_(1)V_(1)-P_(2)V_(2)ubrace)quad" (given) "],[" Ist law TD: "q=0" since no neat exchange w/ environment "],[Delta v=U_(2)-U_(1)=lambda^(0)+omega^(2)]:}\begin{aligned} \omega & =\underbrace{P_{1} V_{1}-P_{2} V_{2}} \quad \text { (given) } \\ \text { Ist law TD: } & q=0 \text { since no neat exchange w/ environment } \\ \Delta v & =U_{2}-U_{1}=\lambda^{0}+\omega^{2}\end{aligned}ω=P1V1−P2V2⏟ (given)  Ist law TD: q=0 since no neat exchange w/ environment Δv=U2−U1=λ0+ω2
rearlang: V 2 + P 2 V 2 ⏟ H 2 = V 1 + P 1 V 1 ⏟ H 1 ⇒ Δ H = H 2 − H 1 = O since H 2 = H 1 V 2 + P 2 V 2 ⏟ H 2 = V 1 + P 1 V 1 ⏟ H 1 ⇒ Δ H = H 2 − H 1 = O  since  H 2 = H 1 quadubrace(V_(2)+P_(2)V_(2)ubrace)_(H_(2))=ubrace(V_(1)+P_(1)V_(1)ubrace)_(H_(1))=>{:[Delta H=H_(2)-H_(1)=O],[" since "H_(2)=H_(1)]:}\quad \underbrace{V_{2}+P_{2} V_{2}}_{H_{2}}=\underbrace{V_{1}+P_{1} V_{1}}_{H_{1}} \Rightarrow \begin{aligned} & \Delta H=H_{2}-H_{1}=O \\ & \text { since } H_{2}=H_{1}\end{aligned}V2+P2V2⏟H2=V1+P1V1⏟H1⇒ΔH=H2−H1=O since H2=H1
Total elevivotive of H H HHH as function of P , T : H ( P , T ) P , T : H ( P , T ) P,T:H(P,T)P, T: H(P, T)P,T:H(P,T)
d H = ( ∂ H ∂ P ) T d P + ( ∂ H ∂ T ) P d T Apply: ( ∂ H ∂ T ) P = C P ∗ Recall d H = 0 d T = − 1 C P ( ∂ H ∂ P ) T d P d H = ( ∂ H ∂ P ) T d P + C P d T − C P d T = ( d H ∂ P ) T d P − d H This is a total differential, but because this is a special case of d H = 0 ( constant H ) , can rewrite: ( ∂ T ∂ P ) H = − 1 C P ( ∂ H ∂ P ) T d T = − 1 C P ( ∂ H ∂ P ) T d P + 1 C P d H μ S T = ( ∂ T ∂ P ) H is called the Joules-Thonson coefsicient. It measures the change in temperature with respect to a change in pressure in a Jolles-Thomson expansion. Δ H = 0 for Joules-Thomson expansions d H = ∂ H ∂ P T d P + ∂ H ∂ T P d T  Apply:  ∂ H ∂ T P = C P ∗  Recall  d H = 0 d T = − 1 C P ∂ H ∂ P T d P d H = ∂ H ∂ P T d P + C P d T − C P d T = d H ∂ P T d P − d H  This is a total differential, but because this is a special case of  d H = 0 (  constant  H ) , can rewrite:  ∂ T ∂ P H = − 1 C P ∂ H ∂ P T d T = − 1 C P ∂ H ∂ P T d P + 1 C P d H μ S T = ∂ T ∂ P H  is called the Joules-Thonson coefsicient. It measures   the change in temperature with respect to a change in   pressure in a Jolles-Thomson expansion.  Δ H = 0  for   Joules-Thomson expansions  {:[dH=((del H)/(del P))_(T)dP+((del H)/(del T))_(P)dT quad" Apply: "((del H)/(del T))_(P)=C_(P)quad**" Recall "dH=0],[dT=(-1)/(C_(P))((del H)/(del P))_(T)dP],[dH=((del H)/(del P))_(T)dP+C_(P)dT],[-C_(PdT)=((dH)/(del P))_(T)dP-dH],[" This is a total differential, but because this is a special case of "dH=0],[(" constant "H)", can rewrite: "quad((del T)/(del P))_(H)=(-1)/(C_(P))((del H)/(del P))_(T)],[dT=-(1)/(C_(P))((del H)/(del P))_(T)dP+(1)/(C_(P))dH],[mu_(ST)=((del T)/(del P))_(H){:[" is called the Joules-Thonson coefsicient. It measures "],[" the change in temperature with respect to a change in "]:}],[" pressure in a Jolles-Thomson expansion. "Delta H=0" for "],[" Joules-Thomson expansions "]:}\begin{aligned} & d H=\left(\frac{\partial H}{\partial P}\right)_{T} d P+\left(\frac{\partial H}{\partial T}\right)_{P} d T \quad \text { Apply: }\left(\frac{\partial H}{\partial T}\right)_{P}=C_{P} \quad * \text { Recall } d H=0 \\ & d T=\frac{-1}{C_{P}}\left(\frac{\partial H}{\partial P}\right)_{T} d P \\ & d H=\left(\frac{\partial H}{\partial P}\right)_{T} d P+C_{P} d T \\ & -C_{P d T}=\left(\frac{d H}{\partial P}\right)_{T} d P-d H \\ & \text { This is a total differential, but because this is a special case of } d H=0 \\ & (\text { constant } H) \text {, can rewrite: } \quad\left(\frac{\partial T}{\partial P}\right)_{H}=\frac{-1}{C_{P}}\left(\frac{\partial H}{\partial P}\right)_{T} \\ & d T=-\frac{1}{C_{P}}\left(\frac{\partial H}{\partial P}\right)_{T} d P+\frac{1}{C_{P}} d H \\ & \mu_{S T}=\left(\frac{\partial T}{\partial P}\right)_{H} \begin{array}{l} \text { is called the Joules-Thonson coefsicient. It measures } \\ \text { the change in temperature with respect to a change in } \end{array} \\ & \text { pressure in a Jolles-Thomson expansion. } \Delta H=0 \text { for } \\ & \text { Joules-Thomson expansions } \end{aligned}dH=(∂H∂P)TdP+(∂H∂T)PdT Apply: (∂H∂T)P=CP∗ Recall dH=0dT=−1CP(∂H∂P)TdPdH=(∂H∂P)TdP+CPdT−CPdT=(dH∂P)TdP−dH This is a total differential, but because this is a special case of dH=0( constant H), can rewrite: (∂T∂P)H=−1CP(∂H∂P)TdT=−1CP(∂H∂P)TdP+1CPdHμST=(∂T∂P)H is called the Joules-Thonson coefsicient. It measures  the change in temperature with respect to a change in  pressure in a Jolles-Thomson expansion. ΔH=0 for  Joules-Thomson expansions