Quick Conceptual Question on Ideal Gases

Click For Summary

Discussion Overview

The discussion revolves around the conceptual understanding of ideal gases, specifically addressing why the volume of an ideal gas is considered unimportant. Participants explore the implications of the ideal gas model and its assumptions, particularly in relation to the identity and interactions of gas particles.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Megan questions the reasoning behind the assertion that the volume of an ideal gas is not important, referencing her textbook's explanation related to the identity of gas particles.
  • One participant explains that in an ideal gas, individual particles are assumed to take up no space, suggesting this simplifies calculations, particularly at low pressures.
  • Another participant introduces the Van der Waals equation, which accounts for particle volume and intermolecular attractions, indicating that these factors become significant at high pressures and densities.
  • Several participants express confusion about the concept of particles having no space, with one noting that this is an approximation similar to ignoring other factors in physics, like air resistance.
  • It is reiterated that the ideal gas model allows for the use of the equation PV = nRT without concern for the gas's identity or intermolecular forces.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the concept of volume in ideal gases, with some agreeing on the approximation while others remain confused about its implications. No consensus is reached on the clarity of the concept.

Contextual Notes

Participants highlight that the ideal gas model is a simplification and may not hold true under all conditions, particularly at high pressures or when considering real gas behavior.

meganw
Messages
96
Reaction score
0

Homework Statement



Why is the volume of an ideal gas not important?

I'm just asking this for my own studying benefit, it's not technically "homework", although we are studying it.

My book says that we can draw the fact that the volume of an ideal gas is not important from the fact that an ideal gas is not affected by the identity (structure) of the gas particles..

I don't get it. :-/

Thanks for any help! =)

-Megan
 
Physics news on Phys.org
In an ideal gas you assume that individual particles (atoms/molecules) take up no space.
This is just a cheat to make the maths easier, but for low pressures it is accurate.

There is an advanced form of the gas law equations, Van der Waals equation, which includes addiational terms to account for the volume of the particles and the attraction betwene them.
the difference becomes important at high pressures/densities when the atoms are close together.
 
What? How can something have no space?
 
meganw said:
What? How can something have no space?

Many people are perplexed about the same thing ... it's an approximation. If you are in General Chemistry ignore Van Der Waal.

Ideal gas is in reference to the postulate that the identity of the gas does not matter and that they would not be attracted to each other via intermolecular attractions.

Basically , the point of the argument is that if something is an ideal gas you don't need to worry about the identity of the gas ... if the question claims an ideal gas simply use PV = nRT.
 
meganw said:
What? How can something have no space?

It's an approximation, it's like ignoring air resistance or the mass of the spring - except it's a very good approximation for stp.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
16
Views
4K
  • · Replies 3 ·
Replies
3
Views
7K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K