Thermodynamics class 11 physics
- 1. THERMODYNAMIC PROCESSES By Mohammed Afzal 11A
- 6. Depends on amount of matter. Eg;- Mass,Vol,Moles,Heat Capacity,Energy,Enthalpy,Entropy,Gibbās Free Energy,Internal energy Does not depend on matter. Eg:- Density,Refractive index, specific heat capacity,pressure,temp,viscosity,concentra tion Molarity,Molality,mole fraction,normality,molar entropy,molar enthalpy,internal energy. Extensive: Intensive:
- 7. Depends on initial and final state of a system. Does not depend on path of flow. Eg:- Pressure(P),Temp(T),Volume(V),moles(n), Enthalpy(H),Entropy(S),Internal Energy(U),Gibbs Free Energy(G) Depends on path of flow. Eg:-Heat(Q),Work(W) State Functions: Path Functions:
- 9. Gram SHC : c = Q/mĪT Molar SHC : C = Q/nĪT Cisothermal -> ā Cadiabatic = 0 (For gases) c = 4.2 J/g Ā°C (Water) cv = Q/mĪT (At constant vol) Cv = Q/nĪT (At constant vol) cP = Q/mĪT (At constant pressure) CP = Q/nĪT (At constant pressure) Cv=Mcv CP=McP CP - CV = R CV = (f/2)R CP = (f/2 + 1)R Ī³=CP/CV Specific Heat Capacity:
- 10. f(degree of freedom) Cv = (f/2)R CP = CV + R Ī³=CP/CV 3(Monoatomic) 3R/2 5R/2 5/3 = 1.66 5(Diatomic) 5R/2 7R/2 7/5 = 1.4 6(Polyatomic) 7R/2 4R 4/3 = 1.33 Ī³= 1 + 2/f
- 11. PV Graph for all processes: P V Isobaric Isochoric Isobaric:ĪP=0 Isochoric:ĪV=0 Isothermal:ĪT=0 Adiabatic:ĪQ=0
- 12. Occurs in infinitely small steps -> Infinite time to finish. Slow Each step in equilibrium. Not practical. W = - ā« Pext dV Occurs at once -> finite time. Fast Equilibrium initially and finally only. Practical situation. W = - šØpĪV Reversible Process: Irreversible Process:
- 14. Heat given to the system -> +ve Heat given by the system -> -ve Work done on a system -> +ve Work done by a system -> -ve Conventions:
- 15. W=PV relation: Pext = F/A ā¹ F = Pext x A W = F Īx = Pext A Ī x ā¹ W = - Pext ĪV Why -ve? By convention
- 16. P V dV P ā« dW = ā« P dV W = - ā« Pext dV = Area under P-V Graph Expansion: W = -ve Compression: W = +ve
- 17. Cyclic Process: P V Wnet = Area of shape(ie square in this case) enclosed -ve for clockwise (as in this case) +ve for anti-clockwise
- 18. Isobaric(Īp=0): W= -Pext ĪV Isochoric(ĪV=0): W = 0 Vacuum(Free Expansion):Pext = 0 ā¹ W = 0 Isobaric and Isochoric processes:
- 19. W = - ā« Pext dV = - ā« nRT dV/V = - nRT ln (V2/V1) = - 2.303 nRT log10 (V2/V1) = - 2.303 nRT log10 (P2/P1) = - 2.303 P1V1 log10 (V2/V1) = - 2.303 P2V2 log10 (V2/V1) = - 2.303 P1V1 log10 (P2/P1) = - 2.303 P2V2 log10 (V2/V1) Isothermal process