How Do We Calculate Entropy Change for an Ideal Gas?

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SUMMARY

The entropy change for an ideal gas involving n moles is calculated using the formula ΔS = nCvln(T2/T1) + nRln(V2/V1). This equation incorporates the first law of thermodynamics, where ΔS represents the change in entropy, qrev is the reversible heat transfer, and T is the temperature. The terms nCvln(T2/T1) and nRln(V2/V1) arise from the specific heat at constant volume and the ideal gas law, respectively. The discussion highlights confusion regarding the derivation of these terms without explicit mention of the process type, such as isothermal conditions.

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Homework Statement


The question says:
In a process involving n moles of an ideal gas , what is the entropy change of the system ?

Homework Equations


ΔS=qrev/T=(ΔU-w)/T
(I have used the chemistry's equation of 1st law of thermodynamics which has the -ve sign)

The Attempt at a Solution


The answer given is that:
nCvln(T2/T1)+nRln(V2/V1).
I don't know how they are giving this answer. The second term seems to be originated from work done in isothermal conditions . But its not given that the process is an isothermal one. And the first term ...huh..I don't know where it came from. So what is the origin of this answer?
 
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mooncrater said:
In a process

What process?
 
Borek said:
What process?
There is nothing else given in the question.
 

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