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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: m190908m on March 09, 2018, 06:45:58 PM

Title: Internal Energy Problem Help
Post by: m190908m on March 09, 2018, 06:45:58 PM

Internal Energy Problem.. A chemical reaction occurs, 25.5 KJ of energy is exchanged between the system and surroundings...

given:

Pressure: 3.50 atm

L*atm= 101.32 J

w= -pDeltaV

temperature change: 7.6 Kelvin

What is the change in internal energy?
This one's really stumping me. Any help would be appreciated. Even just a hint.
I've tried rearranging the pv work equation, I've tried rearranging the change internal equation. Actually just not sure where the temperature fits into all this. I understand most of this. This isn't like any internal energy problem I've run into..

Title: Re: Internal Energy Problem Help
Post by: m190908m on March 09, 2018, 07:12:14 PM

Here's work

Title: Re: Internal Energy Problem Help
Post by: m190908m on March 09, 2018, 07:13:51 PM

Side note: I'm not even sure if this problem is possible to solve without more info

Title: Re: Internal Energy Problem Help
Post by: Borek on March 10, 2018, 03:34:26 AM

Quote from: m190908m on March 09, 2018, 07:13:51 PM

Side note: I'm not even sure if this problem is possible to solve without more info

Thermodynamics is definitely not my forte, but at first sight I don't see how to solve this one as well.

Title: Re: Internal Energy Problem Help
Post by: jestearns on March 14, 2018, 02:17:19 AM

Doesn't provide enough information to make sense of what's going on.  If work is being done, what is moving?  Is the reaction being conducted within a piston where ideal gas can be assumed?  If so, w = pΔV = nRΔT.  What is the direction of the energy exchange in regards to the system and the surroundings?