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

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In an adiabatic transformation, the first law of thermodynamics states that the change in internal energy (ΔU) equals the negative of work done (W), leading to the equation ΔU = -W since heat transfer (Q) is zero. This results in the relationship W = -ΔU = n·C_v(T_1 - T_2), where C_v is the specific heat at constant volume and n represents the number of moles. The discussion highlights confusion regarding the absence of 'n' in some formulations and suggests that the equation may be interpreted as "per mole" or "per unit mass." Participants emphasize the importance of understanding the definitions and derivations of these thermodynamic concepts, encouraging individual research and comprehension.
Ruby_338
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How come ##adiabatic \,work = C_v(T_2 -T_1)##
 
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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
 
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.
 
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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?
 
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Isn't it straightforward? How is C_v defined? What is nC_v\Delta T?
 
I don't know XD
 
Then start by checking. Per forum rules you should do your legwork, not ask others to do that for you.
 
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Okay. Ill remember that
 
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