## change in enthalpy

Ekayana Sethi 2K
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### change in enthalpy

is delta(H)=delta(U)-delta(n)*R*T or delta(H)=delta(U)+delta(n)*R*T? Also is work -P*delta(V) or +P*delta(V)?

Ashley Davis 1I
Posts: 57
Joined: Fri Sep 29, 2017 7:04 am

### Re: change in enthalpy

for the second part of your question, i believe w = -PΔV when work is done BY the system and w = +PΔV when work is done ON the system.

AtreyiMitra2L
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### Re: change in enthalpy

I believe it is deltaU = deltaH - delta(n)RT. This goes off of the concept that delta u is equal to q + w. (AKA the second one). Work is the second one. This occurs because of the idea of what the work is being done on or by what. In expansion, the work is being done ON the surroundings BY the system. Therefore, it is negative.

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