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### internal energy

Posted: Tue Jan 16, 2018 8:56 pm
How do you find the change of internal energy?

### Re: internal energy

Posted: Tue Jan 16, 2018 8:58 pm
deltaU=q+w

### Re: internal energy

Posted: Tue Jan 16, 2018 9:57 pm
The change in internal energy of a system (Delta U) is the sum of the heat (q) added (q > 0) to or
removed (q < 0) from the system and the work (w) done on (w > 0) or by (w < 0) the system. In short, delta U = q + w.

### Re: internal energy

Posted: Wed Jan 17, 2018 1:13 am
Sorry this is a little off topic but does this make Internal energy, or the change in internal energy not a state function because both heat and work are not state functions?

### Re: internal energy

Posted: Wed Jan 17, 2018 9:28 am
Internal energy still is considered a state function despite both heat and work being path-dependent. I believe that because internal energy is not path-dependent (and only state-dependent), it does not matter what combination of heat and work is present to sum to the internal energy.

### Re: internal energy

Posted: Wed Jan 17, 2018 1:48 pm
Internal energy is a state property because it is a property intrinsic to a system. And as said above, the value of internal energy is not dependent on how that value was reached -- it is path independent.