Adiabatic Expansion Question


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Helen_Lee_1L
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Joined: Wed Sep 21, 2016 3:00 pm

Adiabatic Expansion Question

Postby Helen_Lee_1L » Sun Jan 29, 2017 8:14 pm

In an adiabatic expansion, the volume goes from 1 Liters to 2.56 Liters at an external pressure of 1 atm. It releases 73J of heat at 1 atm, and returns to its original delta U. Find final volume.

So I understand that in an adiabatic expansion q=0, and so delta U equals work. Therefore, work (w) equals negative external pressure times delta volume. What would I have to do if I have to find the delta U if we are not give the energy?

104733470
Posts: 9
Joined: Wed Sep 21, 2016 3:00 pm

Re: Adiabatic Expansion Question

Postby 104733470 » Sun Jan 29, 2017 8:22 pm

Since there is no enthalpy, change in internal energy relies on work. and if external pressure is constant then work equales p times delta v (change in volume). Thats it. if pressure is not constant then work is nRln(v2/v1).


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