Heat Storage Capacity of CO2 molecules

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Discussion Overview

The discussion centers on the heat storage capacity of CO2 molecules, particularly in the context of their role in global warming. Participants explore the concept of energy storage in individual CO2 molecules at a specified temperature, addressing both theoretical and practical implications.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant seeks to calculate the maximum amount of IR energy that a single CO2 molecule can store at 20°C, providing specific heat capacity and mass values.
  • Another participant argues that discussing the heat capacity of a single molecule is not meaningful, as heat capacity is a bulk property and energy is quickly lost through collisions with other molecules.
  • A later reply emphasizes that CO2 does not store electromagnetic IR energy in a conventional sense and mentions the bond-dissociation energy of CO2 as a limit for energy absorption.
  • One participant suggests that if CO2 were effective at storing thermal energy, it could potentially reduce global warming, but questions the premise of the original inquiry.

Areas of Agreement / Disagreement

Participants express disagreement regarding the relevance and meaning of heat storage in individual CO2 molecules. There is no consensus on the original question, with multiple competing views on the role of CO2 in energy absorption and its implications for global warming.

Contextual Notes

Participants highlight limitations in the original question's framing, particularly regarding the nature of energy storage in molecules and the implications for the greenhouse effect. The discussion remains unresolved on the specific calculations requested.

Ellsworth
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I am a science hobbyist and working on a paper to illustrate the impact of CO2 on Global Warming.

Question – What is the Storage Capacity in joules, of one molecule of CO2 @ 20c/68f/293k. In other words, what is the maximum amount of IR energy that one molecule of CO2 can store at this temperature.

The mass of one molecule of CO2 is 7.308 x 10^-23g or 7.308 x 10^-26kg and the Specific Heat Capacity of CO2 is 834 at constant pressure (J kg-1K-1)

In essence, I am looking for both the value and the formula for which to use in order to calculate this.

For the cherry on top, how long can it store this amount of energy
 
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It is not meaningful to talk of the heat capacity of one molecule. (Why do you want to, anyway?) Heat capacity is a bulk property.

Heat isn't stored in CO2 molecules. When a CO2 molecule absorbs IR radiation it quickly loses the excess energy by collisions with other molecules in the air, so the atmosphere warms up.
 
Hi M, thanks for the note. I should have properly worded the question to read, "In other words, what is the maximum amount of Electromagnetic IR energy that one molecule of CO2 can store at this temperature. Trying to get the feel for significance of what you described in terms of joules of energy. Thanks Ellsworth
 
Ellsworth said:
Hi M, thanks for the note. I should have properly worded the question to read, "In other words, what is the maximum amount of Electromagnetic IR energy that one molecule of CO2 can store at this temperature. Trying to get the feel for significance of what you described in terms of joules of energy. Thanks Ellsworth
That is still strangely worded. A molecule doesn't store "electromagnetic IR energy." Also, it is strange to think about the role of CO2 in the greenhouse effect in terms of heat capacity.

Strictly speaking, the bond-dissociation energy of CO2 is 5.51 eV, so this is more or less the maximum energy a molecule of CO2 could absorb from IR radiation before breaking apart.

mjc123 said:
Heat isn't stored in CO2 molecules. When a CO2 molecule absorbs IR radiation it quickly loses the excess energy by collisions with other molecules in the air, so the atmosphere warms up.
I would argue that this is not the main factor in the greenhouse effect. It is rather the fact that the CO2 will reemit the IR radiation in all direction, including back towards the surface.
 
If CO2 were unusually good at storing thermal energy, it would reduce global warming.

As worded though, it appears to me the answer to the OP's question is zero.
 

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