Question

Do you know where can I find how to get relations between heat capacities Cp and Cv for ideal and real gases?
Or someone can write it here?

Answer 1

You can always start with Cv=3/2R for a monatomic particle and use Cp=Cv+R.
Cv= 5/2R for Diatomic
CV= 3R for Polyatomic
R is a constant that you know right?
Cheers :D

Answer 2

I have to show why is it Cp=Cv+nR for ideal gas and why it is what it is for real gas.

I found this, and I am ok with ideal gas... but I am not really clear with real gas :/

Answer 3

OooOOooo, That complicates things then :( I'm not sure I can help you further, sorry
Cheers :D

Answer 4

thanks anyway :)

Answer 5

hope this will help you out , hold a sec

Answer 6

if you are not able to read it , let me know :)

Answer 7

I think I found what I was looking for... via coefficient of volume expansion
Thank you very much

Answer 8

\[h= u+PV\]\[dh=du+d(PV)\]
\[dh=du+d(RT), dh=du+RdT\]\[\frac{ dh }{ dT }=\frac{ du }{ dT }+R\]\[C _{p}=C _{v}+R,
C _{p}-C _{v}=R\]
you can use this derivation too

Answer 9

and you are welcome :)

Answer 10

what is h?

Answer 11

h-- enthalpy
u -- internal energy
dh/dT -- Cp
du/dT-- Cv

Answer 12

is Cp defines as dh/dT or we get it somehow because p=const?

Answer 13

*defined

Answer 14

yep, Cp is specific heat capacity at constant pressure, and change in enthalpy at with temperature is the same quantity , for ideal gas
dh=CpdT
and gamma = Cp/Cv

Answer 15

ok. I will read this all again and if I have more questions, I will write them tomorrow, ok? :) thank you again :)

Answer 16

sure :)

Answer 17

do you maybe have graphs of isotherms of Van der Waals gas and real isotherms and something about thermometer with thermocouple, I can't find it on internet?

Answer 18

http://bcs.whfreeman.com/chemicalprinciples3e/content/lgraphs/E3004.html

Answer 19

http://adf.ly/3336544/banner/http://www.adichemistry.com/physical/gaseous/deviation/van-der-waals-equation.html

Answer 20

:) thanks :)