<p>The temperature of three moles of an ideal gas is 373 K. How much work does the gas do in expanding isothermally to four times its initial volume?</p>
<p>Work = P<em>change in V
find the initial PV and then multipy it by 4
PV=nRT = 3moles</em>8.3145J/mol*K *373K
then it expands to 4 times its original volume so just multiply that by 4</p>
<p>Mattd is wrong. Work is the integral of P dV. Since pressure is not constant, you cannot work the problem that way. If it was an isobaric process you could, but it is not, so you can't. I'm assuming, since you're asking this as an AP Physics problem, and, to my knowledge, only Physics B covers Thermodynamics, that you have not had calculus, so I can't really explain it fully, but this integral reduces to give you a nice little formula for work:</p>
<p>W=-nRT ln[Vf/Vi] = -pi Vi ln[Vf/Vi] = -pf Vf Ln[Vf/Vi] </p>
<p>Use whichever works best for the problem. In this case, the first probably makes the most sense. And if you actully have had calculus, let me know, and I can show you the derivation if you'd like.</p>