Chemistry Graph of several thermodynamic processes

  • Thread starter Thread starter tellmesomething
  • Start date Start date
  • Tags Tags
    Thermodynamics
Click For Summary
The discussion revolves around the interpretation of a thermodynamic graph depicting various processes. A key question raised is whether state D would have the same pressure as state A if the process from A to D was not included. Participants clarify that in a reversible system, pressure and volume can be returned to their original states, provided temperature remains constant. Misinterpretations of the graph, particularly regarding the direction of arrows and the nature of isochoric and isobaric processes, are addressed. Ultimately, the consensus is that the pressure at state A influences the final state D, especially considering the isochoric process involved.
tellmesomething
Messages
449
Reaction score
68
Homework Statement
Graph these processes on a PV graph : Isothermal expansion from state A to B, isochoric pressure increment from B to C,
isothermal contraction from C to D, isobaric contraction from D to A.
Relevant Equations
!!!
I graphed it similar to this

IMG_20240314_204917.jpg


My query is say if the last process wasn't mentioned, I.e the process from A TO D, would the state D have the same pressure as state A then? In thermodynamics for a reversible system we say that if it undergoes a change in pressure volume the exact pressure and volume can he achieved when we reverse it, considering the temperature is constant. But here since we underwent an isochoric process from B to C and then reversed it, would it have ended at the same pressure of A if not for the last condition?
 
Last edited:
Physics news on Phys.org
Did you post the picture you intended to post?
I see the arrows going in the wrong direction, isochoric (at the same volume) and isobaric (at the same pressure) misinterpreted, etc...
 
BvU said:
Did you post the picture you intended to post?
I see the arrows going in the wrong direction, isochoric (at the same volume) and isobaric (at the same pressure) misinterpreted, etc...
Oh, sorry my question is typed wrong

[Post edited by a Mentor]
 
Last edited by a moderator:
BvU said:
Did you post the picture you intended to post?
I see the arrows going in the wrong direction, isochoric (at the same volume) and isobaric (at the same pressure) misinterpreted, etc...
All fixed! Please give it another read i interchanged D & B by mistake
 
BvU said:
Did you post the picture you intended to post?
I see the arrows going in the wrong direction, isochoric (at the same volume) and isobaric (at the same pressure) misinterpreted, etc...
Hi, if you have some free time, please consider clearing my doubt. Thankyou.
 
Back from a short vacation, but I think we need more expertise. @Chestermiller ?
 
  • Like
Likes tellmesomething
Fwiw: CD is an isothermic volume reduction down to a particular pressure. Whoever executes the cycle can choose that pressure; since DA is supposed to be isochoric, the choice of P at A makes sense.
 
  • Like
Likes tellmesomething
BvU said:
Back from a short vacation, but I think we need more expertise. @Chestermiller ?
It seems to me the graph in post #1 is correct, except BC should be vertical.
 
  • Like
Likes BvU and tellmesomething
BvU said:
Fwiw: CD is an isothermic volume reduction down to a particular pressure. Whoever executes the cycle can choose that pressure; since DA is supposed to be isochoric, the choice of P at A makes sense.
That was the doubt if pressure would have remained the same if the last isochoric condition wasnt there. Got it. thanks
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
9
Views
2K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 60 ·
3
Replies
60
Views
9K
Replies
4
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K