Heat Storage Capacity of CO2 molecules

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SUMMARY

The heat storage capacity of a single CO2 molecule at 20°C (293K) is effectively negligible, as heat is not stored in CO2 molecules. Instead, when CO2 absorbs infrared (IR) radiation, it quickly dissipates energy through collisions with surrounding molecules, contributing to atmospheric warming. The bond-dissociation energy of CO2 is approximately 5.51 eV, representing the maximum energy a CO2 molecule can absorb before breaking apart. The discussion emphasizes that the greenhouse effect is primarily due to CO2's ability to reemit IR radiation rather than its capacity to store thermal energy.

PREREQUISITES
  • Understanding of thermodynamics, specifically heat capacity concepts.
  • Knowledge of infrared radiation and its interaction with gases.
  • Familiarity with molecular physics, particularly bond-dissociation energy.
  • Basic principles of the greenhouse effect and atmospheric science.
NEXT STEPS
  • Research the bond-dissociation energy of various greenhouse gases.
  • Learn about the mechanisms of energy transfer in gases, focusing on collision theory.
  • Explore the greenhouse effect in detail, including the role of different gases.
  • Investigate the specific heat capacities of other atmospheric components.
USEFUL FOR

Science hobbyists, environmental scientists, and students studying climate change and atmospheric chemistry will benefit from this discussion.

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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