- #1

mooncrater

- 217

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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=q

_{rev}/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:

nC

_{v}ln(T

_{2}/T

_{1})+nRln(V

_{2}/V

_{1}).

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?