## Calc heat functions

$w=-P\Delta V$
and
$w=-\int_{V_{1}}^{V_{2}}PdV=-nRTln\frac{V_{2}}{V_{1}}$

Mya Majewski 1L
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Joined: Fri Sep 25, 2015 3:00 am

### Calc heat functions

When do you know when to use q=-q, mcdeltaT=-mcdeltaT, or q=ndeltaH + mcdeltaT????

Chem_Mod
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### Re: Calc heat functions

q=-q just means that the heat is being lost/gained by a certain component and gained/lost by another component. You would use mC$\Delta T$ and/or n$\Delta H$ depending on whether or not the components in question are going through phase changes, with which you use n$\Delta H$, or are just simply increasing the temperature (ie. liquid going from 273K>373K) use mC$\Delta T$. If both a phase change and an increase in temperature are occurring use both.