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## Homework Statement

The temperature of 2 moles of an ideal gas is 366 K. How much work does the gas do in expanding isothermally to 2 times its initial volume?

______ J

## Homework Equations

I think they are relevant...

W= nRT ln(Vf/Vi)

PV=nRT

Q constant pressure= 3/2 nRT(Tf-Ti) + nR(Tf-Ti)

Q constant volume = 3/2 nR(Tf-Ti) = 0

constant pressure: Cp= 3/2R=R=5/2R

constant volume: Cv=3/2R

## The Attempt at a Solution

Ok, I looked at the problem, and I saw it was isothermal, so according to my textbook I used the formula for it: After plugging in the given values I only got so far...

W=(1.5mol) (8.31 J/mol) (366K) ln (Vf/Vi)

I am pretty much clueless on physics in general, so I my goal isn't to fill in the answer box, but to learn the conceptual ideas behind the process. Like why do you do this or that... Usually responds with just numbers puts me no further in my homework :/

Oh and more on the problem: I remembering my textbook mentioning calculating heat using 2 different formulas based on whether its constant pressure or volume, and then after you get that, you use some different formulas for finding "molar specific heat capacities" to finish solving the problem by pluggin everything in the formula. I dont know if this applies to this current problem or not, but I think its a multi step problem and I dont know what my next move should be because I guess I dont have the basic intuition of thermo.

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