## Difference between L.atm and Joules

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

Hailey Boehm 2H
Posts: 71
Joined: Fri Sep 28, 2018 12:24 am

### Difference between L.atm and Joules

What is L.atm's relevance and why is this what you get when you do work calculations in SI units? Must we always multiply our answers by 101.325 J/ 1 L.atm when we are doing work calculations (like for ex. 4B.5 7th ed.)?

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### Re: Difference between L.atm and Joules

When using the equation w=-P*delta V, the product of the units of pressure (generally atm) and volume (generally Liters) is L.atm. However, since work is defined as the energy to act against some force, the convention is to express work in units of energy (Joules), which is why we must convert L.atm to Joules.

Melody P 2B
Posts: 35
Joined: Fri Sep 29, 2017 7:06 am

### Re: Difference between L.atm and Joules

Yes, you'll always have to multiply the answer in $L\cdot atm$ by 101.33 J to convert into J because as previously mentioned work is typically expressed in Joules. Also, my TA was uncertain as to whether this conversion will be on our equations sheet so that's something to keep in mind.