For more such informative content, go to https://scifitechify.blogspot.com/. This PPT is about thermodynamics. It explains isothermal, isobaric, adiabatic, and isochoric processes. In-depth explanation of formulae and derivation is provided.

1. THERMODYNAMIC PROCESSES
By Mohammed Afzal 11A

2. Introduction:
Conducting Insulating

3. Types of System:
(Diathermic)
1)

4. Types of System:
2)

5. Types of System:
3)

6. Depends on amount of matter.
Eg;- Mass,Vol,Moles,Heat
Capacity,Energy,Enthalpy,Entropy,Gibb’s
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:

8. Cyclic Process:
P
V
ΔP=0
ΔT=0
ΔE=0
ΔV=0
ΔS=0
ΔQ≠0
ΔW≠0

9. Gram SHC : c = Q/mΔT Molar SHC : C = Q/nΔT
Cisothermal -> ∞ Cadiabatic = 0 (For gases) c = 4.2 J/g °C (Water)
cv = Q/mΔT (At constant vol) Cv = Q/nΔT (At constant vol)
cP = Q/mΔT (At constant pressure) CP = Q/nΔT (At constant pressure)
Cv=Mcv CP=McP CP - CV = R CV = (f/2)R CP = (f/2 + 1)R γ=CP/CV
Specific Heat Capacity:

10. f(degree of
freedom)
Cv = (f/2)R CP = CV + R γ=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
γ= 1 + 2/f

11. PV Graph for all processes:
P
V
Isobaric
Isochoric Isobaric:ΔP=0
Isochoric:ΔV=0
Isothermal:ΔT=0
Adiabatic:ΔQ=0

12. Occurs in infinitely small steps -> Infinite
time to finish.
Slow
Each step in equilibrium.
Not practical.
W = - ∫ Pext dV
Occurs at once -> finite time.
Fast
Equilibrium initially and finally only.
Practical situation.
W = - 𝝨pΔV
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 ⟹ F = Pext x A
W = F Δx = Pext A Δ x ⟹ W = - Pext ΔV
Why -ve? By convention

16. P
V
dV
P
∫ dW = ∫ P dV
W = - ∫ 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(Δp=0): W= -Pext ΔV
Isochoric(ΔV=0): W = 0
Vacuum(Free Expansion):Pext = 0 ⟹ W = 0
Isobaric and Isochoric processes:

19. W = - ∫ Pext dV = - ∫ 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

20. Adiabatic Process