Okay, I've been working on this for a while:(adsbygoogle = window.adsbygoogle || []).push({});

Three-tenths mole of an ideal gas at 400K is expanded isothermally from a pressure of 5x10^5 N/m^2 to 1.5x10^5N/m^2. If the gas is then heated to 500K at constant volume and then is compressed isothermally back to 5x10^5 N/m^2, and then isobarically back to the original condition, find the net work of the cycle.

I understand the whole concept of expanding and contracting, but combining the ways that these happen is very confusing to me.

first i found the volume for the first part using the formula V = nRT/P.

so for the first part, when its expanded isothermally i used the formula:

w = nRTln(V2/V1)

w= (3/10)*(8.314)*(400)*ln(6.65*10^-3/2*10^-3)

= 1198.68

same for the second isothermic expansion, except the temperature changed to 500, and therefrore the volume changed and:

w = -1503.58

then for the third part, i used the formula for isobaric gas:

w = P(V2 - V1)

= 245

Then for the net work, I added everything together, and got -364.8

What am I missing here??

Thanks!

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# Homework Help: Ideal gas problem

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