## 2011 Midterm Q1B

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

Moderators: Chem_Mod, Chem_Admin

Amanda Nguyen 2E
Posts: 19
Joined: Tue Nov 25, 2014 3:00 am

### 2011 Midterm Q1B

"1.00 mol of methane is combusted irreversibly at constant room temp. Calculate the work associated with this process."

Why is the change in moles -2.00? Why don't we use 1.00 mol for n?

704628249
Posts: 43
Joined: Fri Sep 25, 2015 3:00 am

### Re: 2011 Midterm Q1B

We'll work for irreversible processes is P x delta V. P delta V is also equal to delta nRT. You can calculate it from there.

Mary Anastasi
Posts: 25
Joined: Fri Sep 25, 2015 3:00 am

### Re: 2011 Midterm Q1B

I think you look at the reaction itself and see that on the reactants side there are 3 moles of gas and on the products side there is 1 mole of gas (seeing that the H2O is liquid), so delta n is -2 moles.

Return to “Calculating Work of Expansion”

### Who is online

Users browsing this forum: No registered users and 2 guests