Thermodynamics - monotomic/diatomig gas heat capacity question

Click For Summary

Discussion Overview

The discussion revolves around the heat capacity differences between monatomic gases, such as helium, and diatomic gases, like hydrogen, particularly in the context of a Grade 12 chemistry homework question. Participants explore the underlying reasons for the varying heat requirements for the same temperature increase in these gases.

Discussion Character

  • Homework-related
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • One participant suggests that the difference in heat capacity may relate to the bonds and the types of energy (rotational, translational, vibrational) present in the molecules.
  • Another participant prompts consideration of the specific heat capacities (CP and CV) of helium compared to other gases.
  • There is a suggestion to examine the intermolecular forces acting between helium molecules and how they compare with those in other gases, although this viewpoint is later challenged.
  • One participant introduces the equipartition theorem as a potentially relevant concept but notes that the original poster is not yet familiar with it.
  • A further inquiry is made regarding the changes that occur when heat is added to a monatomic gas versus a diatomic gas, emphasizing the additional processes that may occur in diatomic molecules.

Areas of Agreement / Disagreement

Participants express differing views on the relevance of intermolecular forces in explaining the heat capacity differences, with some challenging this perspective. The discussion remains unresolved regarding the best approach to understanding the heat capacity of these gases.

Contextual Notes

Participants have not yet established a clear understanding of the equipartition theorem, which may limit the depth of the discussion. Additionally, the relationship between intermolecular forces and heat capacity is contested.

p.ella
Messages
41
Reaction score
0
Thermodynamics -- monotomic/diatomig gas heat capacity question

Homework Statement



GRADE 12 CHEMISTRY: Why would a monotomic gas like Helium require less heat than a diatomic gas like hydrogen to undergo the same temperature increase?


Homework Equations



q=mcΔT


The Attempt at a Solution



I think it has something to do with bonds and rotational/translational/vibrational energy of molecules but don't know exactly help

Thank you everyone!
 
Physics news on Phys.org
Hello p.ella,

The answer to your question maybe twofold.

First ask yourself this: How do the CP and CV values of helium compare with other gases?

Secondly, What kind of inter-molecular forces act between helium molecules? How do they compare with other gases?
 
Sunil Simha said:
Secondly, What kind of inter-molecular forces act between helium molecules? How do they compare with other gases?
Sorry Sunil, but I don't think that intermolecular forces are the right way to go.

p.ella, have you heard of the equipartition theorem?
 
DrClaude said:
Sorry Sunil, but I don't think that intermolecular forces are the right way to go.

p.ella, have you heard of the equipartition theorem?

Thanks anways Sunil :)

And no, I haven't, not yet atleast :)
 
p.ella said:
And no, I haven't, not yet atleast :)
That makes things a bit more difficult, but let's try it this way.

When heat is put into a monatomic gas, what changes?

If you have a diatomic molecule instead, what more can happen (in addition to what you just answered for the monatomic gas)?
 

Similar threads

Replies
1
Views
2K
Replies
2
Views
3K
  • · Replies 2 ·
Replies
2
Views
988
Replies
5
Views
4K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 22 ·
Replies
22
Views
4K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K