Enthalpy: Why Does Temperatures Affect it?

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Homework Help Overview

The discussion revolves around the concept of enthalpy, specifically addressing the relationship between temperature and enthalpy changes in water. Participants are exploring why the enthalpy of water appears to lower as temperature rises, which seems counterintuitive to some initial understandings of thermodynamic principles.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning the fundamental relationship between temperature and enthalpy, with some suggesting that the original poster may have misunderstood the concept. Others are considering the role of entropy in this context and discussing the implications of volume changes on energy requirements.

Discussion Status

The discussion is ongoing, with participants offering differing perspectives on the relationship between enthalpy and temperature. Some guidance has been provided regarding the definitions and implications of enthalpy, but no consensus has been reached on the original question.

Contextual Notes

There appears to be some confusion regarding the definitions and relationships between enthalpy, temperature, and volume, which may be affecting the clarity of the discussion. Participants are also referencing educational experiences to support their points.

arjentje
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I'm breaking my mind on the next question. Why does the enthalpy of water lowers when the temperature rises?

I would say you input heat-energy, so the enthalpy rises. But this does not seem true...
 
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i would dare say you have gotten your information wrongly. Once you heat anything, given that no chemical reaction occurs enthalpy will surely increase.

In case you need prove here's http://www.thermexcel.com/english/tables/eau_atm.htm"
 
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Maybe it was entropy?
 
yeah, seems backwards.

As it was explained to me in my undergrad thermo class, enthalpy is the amount of energy you'd have to use to recreate the substance, including the energy needed to evacuate the volume occupied by the substance.

More volume (by heating) means that you're going to need to take into account a larger amount of energy to evacuate that volume.
 

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