Thermodynamics Flashcards
The co-efficient B in the volume, thermal expansion formula is what?
3a
Zeroth Law
if Ta=Tb and Tb=Tc then Ta=Tc and they are all in thermal equilibrium
Ideal Gas Law
particles don’t interact
Ideal Gas
low density
pressure is less than 1 atm
temp is not near boiling point
Avogadro’s Law
volume of gas at same T and P has same N of particles no matter type of gas
relation to PVT for 1 gas and 2 gas
P1V1/T1=P2V2/T2
Kinetic Theory of Gases
all particles always in motion
Kinetic Theory of Gases applied to the 5 following ideal gas assumptions
particles :
don’t rotate or vibrate
don’t interact
elastic collisions for short t with wall
free to move in any direction
identical particles and large amount
How to find the vrms?
square all the velocities, take the average of that, take square root of that
Mean free path
mean length of straight part of molecules path
Mean Free Time
average time between collision
Diffusion
mix of particles
Can ideal gases change phases? Why?
No because they don’t exert forces on one another
Solid to vapor
Sublimation
Liquid to Gas
Evaporating
Gas to liquid
Liquification
for a phase change if gas temperature is greater/lower than critical tempt gas cannot go to a liquid
greater
on a muggy day there is what
increase water vapor
relative humidity formula
Pwater/Psup x100%
1st law of thermodynamics key 1 pt
work up-work down= w out
2nd law of thermodynamics relates to
entropy never decreases, change in entropy always greater than/equal to 0
entropy is the
disorderness
cold air cannot flow from cold to hot unless
work is done
no perfect ___ exists
100% efficient engine
2nd law of thermodynamics also talks about the fact an engine can never exceed the
carnot engine
3rd law of thermodynamics says there cannot be
a perfect engine
equipartition of energy degrees of freedom what 4 types
translational Ke
rotational Ke
vibrational Ke
vibrational Pe
all active degrees of freedom have
equal energy
energy of a degree of freedom formula
1/2kBT
f of a monotomic and diatomic
3, 5
Cv of a monotomic and diatomic
3k/2, 5k/2
Cp of a monotomic and diatomic
5k/2, 7k/2
y of a monotomic and diatomic
1.67, 1.4
Number of degrees freedom at low temp, room temp, high temp
1,5,7
why are there only 5 degrees of freedom at room temp?
quantum effects preventing vibrational modes being active at these temps
specific heat unit and what it is?
c, amount of heat required to raise 1kg by 1K
molar specific heat unit and what it is?
C, amount of heat required to raise 1 mole by 1K
is there a subscript on molar-specific heat for liquids or solids?
no only v and p for gases
R=?
Cp-Cv
latent heat
amount of E required for a phase change
what does it mean if Q is negative?
heat going from system to environment
during a phase change 3 pts
T is constant
E internal changes
amount of Q=Q transferred to/from each kg of material
Q=…
mc change in temp
adiabatic
Q=0
adiabatic compression
temp increases
isothermal ___ so
change temp=0, tf=ti so change eth=0
isochronic ___ so
change in volume=0,wtot=0
isochronic on a PV diagram is
|
isobaric
change in pressure=0
isobaric on a PV diagram is
_
conduction is molecules…
vibrating due to collisions
the insulator has high or low k
low
the conductor has high or low k
high
convection is
heat transported through the motion of fluids
heat engine e formula
Weng/Qh=(Qh-Qc)/Qh=1-(Qh/Qc)
e carnot=
1-Tc/Th or Th-Tc/Th x100%
refrigerator k
Qc/W= Qc/Qh-Qc
heat pump k
Qh/W= Qh/Qh-Qc
