### Integrals

Posted:

**Fri Jan 15, 2016 7:46 pm**For calculating the work of expansion how do you properly solve an integral? I haven't had CALC in awhile and I forgot how to mathematically solve it.

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=129&t=9793

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Posted: **Fri Jan 15, 2016 7:46 pm**

For calculating the work of expansion how do you properly solve an integral? I haven't had CALC in awhile and I forgot how to mathematically solve it.

Posted: **Fri Jan 15, 2016 7:59 pm**

To calculate the integral you must take the antiderivative {For example, anti derivative of x is (x^2)/2} of the variables on the inside and pull out the constants if you can. Then plug in the values of the bounds you are given.

However, an easier form of the equation for expansion is w=-P delta V

However, an easier form of the equation for expansion is w=-P delta V

Posted: **Sun Jan 17, 2016 12:04 am**

Technically to find work of expansion you have to take the integral of -PV. If P is constant, w=-P. Otherwise, with constant temperature, after integration you will get w=nRTln(V2/V1). And as the above discussion said, it is simply the anti-derivative.