Should diatomic gas be regarded as ideal gas?

  • #1
kelvin490
Gold Member
228
3
We know that one model for ideal gas is monoatomic gas with no attractive force between atoms, elastic collision and some other assumptions. I would like to ask if there exist a gas behave exactly the same but the only difference is it's a diatomic gas (or more complicated structure), should it be regarded as an ideal gas? (Note that the average KE for monoatomic and diatomic gas are different)
 

Answers and Replies

  • #2
21,949
4,996
We know that one model for ideal gas is monoatomic gas with no attractive force between atoms, elastic collision and some other assumptions. I would like to ask if there exist a gas behave exactly the same but the only difference is it's a diatomic gas (or more complicated structure), should it be regarded as an ideal gas? (Note that the average KE for monoatomic and diatomic gas are different)
Yes. We can treat diatomic gases as ideal gases also, if the pressure is low enough. The only difference is in their heat capacity.

Chet
 
  • Like
Likes kelvin490
  • #3
kelvin490
Gold Member
228
3
Yes. We can treat diatomic gases as ideal gases also, if the pressure is low enough. The only difference is in their heat capacity.

Chet

Thanks for the answer. For monoatomic ideal gas the cv is 3R/2 and cp is 5R/2, so γ=5/3 is for monoatomic ideal gas only?
 
  • #4
21,949
4,996
Thanks for the answer. For monoatomic ideal gas the cv is 3R/2 and cp is 5R/2, so γ=5/3 is for monoatomic ideal gas only?
Yes.
 
  • Like
Likes kelvin490

Related Threads on Should diatomic gas be regarded as ideal gas?

  • Last Post
Replies
2
Views
3K
Replies
4
Views
1K
  • Last Post
Replies
8
Views
2K
Replies
11
Views
7K
Replies
25
Views
8K
  • Last Post
Replies
8
Views
4K
Replies
2
Views
29K
Replies
6
Views
2K
Replies
1
Views
7K
  • Last Post
Replies
6
Views
6K
Top