Acetone in water influence its enthelpy of vaporization

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Discussion Overview

The discussion revolves around the influence of acetone in water on its enthalpy of vaporization, particularly in the context of a waste heat recovery device. Participants explore the relationship between acetone's solubility in water, hydrogen bonding, and the thermodynamic properties of the solution.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Mathematical reasoning

Main Points Raised

  • One participant, EJ, suggests that the enthalpy of vaporization of acetone from a solution in water may be greater than that of pure acetone, but seeks specific information on this relationship.
  • Another participant questions whether acetone undergoes hydrogen bonding with water, indicating a potential area of inquiry.
  • A subsequent reply confirms that acetone does indeed undergo hydrogen bonding with water, linking this to its miscibility and suggesting that this interaction could be relevant to understanding enthalpy changes.
  • There is a request for methods to determine the enthalpy of vaporization from the acetone-water solution, indicating a need for more detailed approaches.
  • One participant proposes that examining the vapor pressure of both components as a function of composition and temperature could provide insights into the enthalpy and entropy of the vaporization process, although they acknowledge that this is a preliminary thought.

Areas of Agreement / Disagreement

Participants express varying degrees of uncertainty regarding the specific enthalpy of vaporization of acetone in water and the methods to determine it. There is no consensus on the exact relationship or the best approach to analyze the problem.

Contextual Notes

The discussion lacks specific quantitative data on the enthalpy of vaporization of acetone in solution, and the participants have not resolved the mathematical steps necessary to derive this information from vapor pressure data.

ejnovek
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Hi Everyone,

I'm currently developing a waste heat recovery device as a side project. The system I've created uses a solution of acetone and water. One step in the process involves vaporizing acetone from the water at a low grade heat temperature (note: acetone does not form an azeotrope with water).

Based on the fact that the acetone is dissolved in water, I've assumed that the enthalpy of vaporization of acetone from solution would be greater than if acetone were not in solution.

However, I have been unable to find specific information on the enthalpy of vaporization of acetone dissolved in water and how this energy changes depending on the ratio of acetone to water in solution.

If anyone can find some or all of this information it would be greatly appreciated!

Thanks,

EJ
 
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Does acetone undergo hydrogen-bonding with water?
 
Yes, acetone does undergo hydrogen bonding with water and that is the reason acetone is miscible in water. This paper details the binding energy between acetone and water:https://www.researchgate.net/publication/228425952_Theoretical_analysis_of_the_hydrogen_bond_interaction_between_acetone_and_water

How can information on hydrogen bonding be used to determine the enthalpy of vaporization of acetone in water?
 
Last edited by a moderator:
How do you determine the enthalpy of vaporization of the acetone from the acetone-water solution?
 
A quick thought or two, without thinking it through in detail: If you can find information on the vapor pressure of both water and acetone as a function of composition and temperature you might be able to tease out the enthalpy and entropy of the process.

Basically, the vapor pressure can be related to the Gibbs free energy and the entropy can be related to the temperature coefficient of the Gibbs free energy. Subtracting the TS term will give you the entropy.

As I mentioned, I have not thought this through in detail, so please just consider it a hint as to how one might proceed.
 

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