How do I find the work done in an adiabatic process?

In summary: ThanksIn summary, for an adiabatic process, the change in internal energy is equal to the negative of the work done, which is equal to the specific heat for constant volume multiplied by the change in temperature, multiplied by the number of moles. This follows from the second law of thermodynamics, where heat is equal to zero in an adiabatic process. It is strange that the formula given does not include the number of moles, as it is an important factor in calculating the work done.
  • #1
Ruby_338
27
2
How come ##adiabatic \,work = C_v(T_2 -T_1)##
 
Chemistry news on Phys.org
  • #2
If the transformation is adiabatic you have that ##\Delta U=-W## for the second law of thermodynamics because ##Q=0##. So ##W=-\Delta U = n\cdot C_{v}(T_{1} -T_{2})## where ## C_{v}## is the specific heat for constant volume and ##n## represents the mole. It is strange that in your formula there isn't ##n##...

Ssnow
 
  • #3
Ssnow said:
If the transformation is adiabatic you have that ##\Delta U=-W## for the second law of thermodynamics because ##Q=0##. So ##W=-\Delta U = n\cdot C_{v}(T_{1} -T_{2})## where ## C_{v}## is the specific heat for constant volume and ##n## represents the mole. It is strange that in your formula there isn't ##n##...

Ssnow
Maybe he means "per mole" or "per unit mass.". Also, irrespective of the 2nd law, Q is equal to zero for an adiabatic process.
 
  • Like
Likes Ssnow
  • #4
I forgot to add the n. How did we get ## - \Delta U = n C_v (T_2-T_1) ## ?

Can you show me step by step?
 
Last edited by a moderator:
  • #5
Isn't it straightforward? How is [itex]C_v[/itex] defined? What is [itex]nC_v\Delta T[/itex]?
 
  • #6
I don't know XD
 
  • #7
Then start by checking. Per forum rules you should do your legwork, not ask others to do that for you.
 
  • Like
Likes Chestermiller
  • #8
Okay. Ill remember that
 

1. How is work done defined in an adiabatic process?

In an adiabatic process, work done is defined as the energy transferred to or from a system through mechanical means, such as compression or expansion. This can also be thought of as the force applied over a distance.

2. What is the equation for calculating work done in an adiabatic process?

The equation for calculating work done in an adiabatic process is W = -PΔV, where W is work done, P is pressure, and ΔV is the change in volume.

3. How does the work done in an adiabatic process compare to other thermodynamic processes?

In an adiabatic process, there is no transfer of heat, so all the work done is due to changes in pressure and volume. This is different from other thermodynamic processes, such as isothermal or isobaric, where there may be heat transfer and work done simultaneously.

4. Can the work done in an adiabatic process be negative?

Yes, the work done in an adiabatic process can be negative. If the system is expanding, work is being done by the system and the work done will be negative. On the other hand, if the system is being compressed, work is being done on the system and the work done will be positive.

5. How does work done in an adiabatic process relate to the first law of thermodynamics?

The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. In an adiabatic process, there is no heat transfer, so the change in internal energy is solely due to the work done. This means that the work done in an adiabatic process is equal to the change in internal energy of the system.

Similar threads

  • Introductory Physics Homework Help
Replies
19
Views
1K
Replies
22
Views
2K
Replies
1
Views
497
Replies
1
Views
1K
Replies
81
Views
3K
  • Introductory Physics Homework Help
Replies
5
Views
693
  • Introductory Physics Homework Help
Replies
13
Views
694
  • Introductory Physics Homework Help
Replies
7
Views
1K
Replies
8
Views
24K
Back
Top