MSE 202 2019F
Lecture #1
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Thermodynamics
Thermodynamics:
 Describes ___________ properties of
___________ systems
 Entirely ___________
 Built on ___________ and mathematics
0th Law  Defines ____________________
1st Law  Defines ____________________
2nd Law  Defines ____________________
3rd Law  Gives ____________________
These laws are ____________________, they ___________ be circumvented.
Lecture #1
Definitions:
● System: ____________________
●
Surroundings: ____________________
●
Boundary: ____________________
Systems can be:
● Open: ____________________ can transfer between the
____________________
● Closed: ____________________ can transfer between the
____________________, but NOT ____________________
● Isolated: ____________________ can transfer between the
____________________
Describing systems requires:
● A few macroscopic properties: ____________________
● Knowledge if System is ____________________
● Knowledge if System is in ____________________
● Knowledge of ____________________
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Lecture #1
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Two classes of Properties:
•
Extensive: ________________________
______________________
•
Intensive: ________________________
_________________
The State of a System at Equilibrium:
•
Defined by the collection of all macroscopic properties that
are described by ________________________
[______________________________of the SYSTEM]
•
For a one-component System, all that is required is
____________________. All other properties then follow.
V = f (_____)
or
p = g(_____)
• Notation:
3 moles
(n=3)
gas
2 Cl2 (g, 5 L, 50 o C)
p=1 bar
,
T=100 oC
5 Ar (s, 5 bar, 50 K)
Lecture #1
Change of State:
(Transformations)
• Notation:
3 H2 (g, 5 bar, 100 oC)
= 3 H2 (g, 1 bar, 50 o C)
_____ state
_____ state
• Path: Sequence of intermediate states
5
p (bar)
1
50
100
T (K)
• Process: Describes the Path
- Reversible
- Irreversible
- Adiabatic
______________________
______________________
______________________
______________________
_____________________
_____________________
- Isobaric
- Isothermal
- Constant Volume
-
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Lecture #1
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Thermal Equilibrium (heat stops flowing)
A
B
A
B
A
B
When a hot object is placed in thermal contact with a cold object, heat flows
from the warmer to the cooler object. This continues
until they are in thermal equilibrium (the heat flow stops). At this point, both
bodies are said to have the same “____________”.
This intuitively straightforward idea is formalized in the __________________
_______________ and is made practical through the development of
thermometers and temperature scales.
===== ZERO’th LAW of Thermodynamics =====
If
then
A
and
B
are in thermal equilibrium and
B
and
C
are in thermal equilibrium,
A
and
C
are in thermal equilibrium.
Consequence of the zero’th law:
B
acts like a ____________, and
at the same “____________”.
A
,
B
, and
C
are all
Lecture #1
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Operational definition of temperature (t)
Need:
(1)
__________________
(2)
__________________
(3)
__________________
(4)
__________________
Example: Ideal Gas Thermometer with the Celsius scale.
Based on ____________________
lim (pV )= constant = f (t )
p →0
t
depends on t
for fixed t
• the substance is a __________________
• f (t ) is the _________
• the __________________ and __________________
of water are the reference points
• the interpolation is __________________
p 0
f(t)=f(0 oC)(1+At)
Experimental result:
A = _________=_________
-273.15
Note:
0 100 C
(t
= −273.15 °C ) is special
t = −273.15 °C is called _______________
Lecture #1
=======
This suggests defining ____________________________
T (K ) = __________________
T = 0K corresponds to _____________________
=======
Better reference points used for the Kelvin scale today are
T = ____________and Ttp = _______________________
p 0
f(Ttp)
0
0
T(K)
______= Ttp
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Lecture #1
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Ideal Gases
Boyle’s Law and the Kelvin scale
valid for all gases for ________
An ideal gas obeys the expression _________at all pressures
(the gas molecules ____________________)
The Ideal gas law
or
This is an example of an equation of state
__________________________
Lecture #1
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Equations of state
IDEAL GAS LAW:
Mixture of ideal gases comprising ni moles of each
Partial pressure of ith gas
mole fraction of i th gas
Dalton’s Law
Real Gases
(a)
(b)
--
do not necessarily obey ideal gas law
Compressibility factor
High T ⇒
__________ dominate
Low T
_________ dominate
⇒
Virial Expansion
generally neglect
B = 0  ideal gas
(neglect C and higher order terms)
Lecture #1
(c)
van der Waals Equation of state
only two parameters, derived from molecular concepts
• First assume “hard sphere” molecules
becomes
• Now put in attraction
So
Rearranging
becomes

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