Constant thermodynamic potentials examples

[dperkovic]

Homework Statement

Specify at least two ( physical or chemical), real world, processes for each of this cases:

a) Internal energy is constant
b) Entalpy is constant
c) Gibbs free energy is constant
d) Helmholtz free energy is constant

Homework Equations

a) dU = TdS - pDV = 0
b) dH = TdS + VdP = 0
c) dG = dH - tdS = 0, or dG =vDp -SdT = 0 ?
d) dF = -(pdV + SdT ) = 0

The Attempt at a Solution

b) Joulle-Thompson effekt

...and this is all what I found...Thanks for any help !

 

[Mapes]

It's not going to help you learn if people just provide the examples for you, so let's try this tack: what's the physical interpretation of $dS=0$? How about $dP=0$, and the others? Can you brainstorm some cases where these restrictions apply? For example, which state variables are constant when an exposed solid melts to form a liquid?

 

[dperkovic]

It's not going to help you learn if people just provide the examples for you, so let's try this tack: what's the physical interpretation of $dS=0$? How about $dP=0$, and the others? Can you brainstorm some cases where these restrictions apply? For example, which state variables are constant when an exposed solid melts to form a liquid?

Maybe it is true, but I think that knowing real world examples help me to better understand thermodynamics. Than, I can compare "mathematics" with real world.

 

[dperkovic]

Maybe it is true, but I think that knowing real world examples help me to better understand thermodynamics. Than, I can compare "mathematics" with real world.

This stand for constant gibbs, am I right ?

 

[Mapes]

Maybe it is true, but I think that knowing real world examples help me to better understand thermodynamics. Than, I can compare "mathematics" with real world.

Sorry, we don't provide answers to homework-type questions. If you show your own effort, however, you'll likely get helpful comments.

 

[dperkovic]

Sorry, we don't provide answers to homework-type questions. If you show your own effort, however, you'll likely get helpful comments.

I'll try, thank you anyway