2. Group 3 :Group 3 :
1.Ainia Rohmah
2.Anggre Tiara O
3.Dewi Puspita
4.Hajar Panca S
5.Millati Azka
6.Nuraini
7.Setyo Aji W.W
8.Toni Wijayanto

4. Isothermal
Isobaric
Isochoric
adiabatic
thermodynamics
definition

5. First law of thermodynamicsFirst law of thermodynamics
First Law of thermodynamics states that :
Whenever heat Q is given to a system, a portion of heat is used to
increase its internal energy in the amount of ∆U, whereas the
remaining leaves the system when the system performs a work W to
its surroundings.
Mathematically, the first law of thermodynamics is formulated by :
Q = ∆U + WQ>0
Q<0
W>0 W<0
W positip jika sistem melakukan usaha
W negatip jika sistem dikenai usaha
Q positip Jika sistem menerima kalor
Q negatip jika sistem melepas kalor
Energi dalam ∆U tidak terpengaruh oleh proses,
yang dilihat adalah hanya pada keadaan awal dan
keadaan akhir

6. The first law of thermodynamics for isothermalThe first law of thermodynamics for isothermal
processprocess
At isothermal Process : ∆T = 0, so ∆U = 0
The work done by the isothermal process is :
,so
Q = ∆U + W = 0 + W = W
Q =
1
2
ln
V
V
nRTW =
1
2
ln
V
V
nRTW =

7. The first law of thermodynamics for isobaricThe first law of thermodynamics for isobaric
processprocess
VPU ∆=∆
2
3
At isobaric process the pressure is constant
DP = 0
Internal energy , so
)(
2
5
2
5
2
3
12 VVPVPQ
VPVPWUQ
−=∆=
∆+∆=+∆=

8. The first law of thermodynamics forThe first law of thermodynamics for
isochoric processisochoric process
At Isochoric process volume is constant, ∆V = 0,
so the work done W = P∆V = 0, its produce :
)(
2
3
2
3
0
12 TTnRTnRUQ
UWUQ
−=∆=∆=
+∆=+∆=

9. The first law of thermodynamics for adiabaticThe first law of thermodynamics for adiabatic
processprocess
Adiabatic process is a process without any transfer
of heat into or from the system (Q=0)and it applies
:
)(
2
3
)(
2
3
0
21
12
TTnRW
TTnRUW
WU
WUQ
−=
−−=∆=−
+∆=
+∆=

11. and