I think this problem has problem

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Homework Help Overview

The discussion revolves around the thermodynamic properties of rubber bands, specifically focusing on the concept of enthalpy in relation to stretching and relaxing the material. Participants are exploring the implications of work done on the rubber band and the associated heat changes.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning the relationship between work done on the rubber band and its enthalpy changes, with some suggesting that stretching may lead to heat absorption from the surroundings upon relaxation.

Discussion Status

The conversation is ongoing, with various interpretations being explored regarding the thermodynamic behavior of rubber bands. Some participants are providing insights into the heat exchange processes involved, while others are questioning the initial assumptions about enthalpy.

Contextual Notes

There appears to be some confusion regarding the definitions of enthalpy and the effects of stretching on temperature, as well as the role of work in heat generation or absorption.

wrrrr95
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Hi guys! I'm a high school student in korea. I was doing homework then, i found that i couldn't understand sth.

When i pull a rubber band, that will make rubber molecules equall but also make them hot.
The problem said 'the entalpy of rubber band when you didnt pull has higher entalpy than you pulled'

Buttttt i think that i worked to the band, so the heat was from work.
It can't define the higher entalpy because of release of heat.

Did i wrong?
 
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Stretch the band and allow it to return to it's original temperature. When you relax the band heat flows into the band from it's surroundings. Therefore it's entalpy increases.
 
Hi wrrr95, http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

wrrrr95 said:
When i pull a rubber band, that will make rubber molecules equall but also make them hot.
Actually, stretching makes them cold. You could concoct a crude refrigerator by stretching rubber bands.
 
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