## change in entropy at constant temperature

1. The problem statement, all variables and given/known data

Calculate the entropy change when 0.011m3 of a perfect gas at a constant temperature of 273K is compressed from an initial pressure 1x10^5 N/m/m to a pressure of 1x10^6 N/m/m.

2. Relevant equations

dS=Q/T

3. The attempt at a solution
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 Recognitions: Gold Member Homework Help Science Advisor Hi ricof, welcome to PF. Can you combine the First Law with what you know about the energy of an ideal gas at constant temperature?
 Some more relevant equations. The first law $$\Delta E=Q+W$$ Work for isothermal expansion $$W=-nRTln\frac{V_{f}}{V_{i}}$$ If you combine this with what you know about change in internal energy at constant temperature, like Mapes said, and that integral of yours, you can figure out the answer.

## change in entropy at constant temperature

Because T is constant, there is no change in internal energy right?

And also, in the above equation for isothermal expansion, how is n calculated?

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