Rate of Pressure Change with Temperature in Ideal Gas Law

Click For Summary

Homework Help Overview

The discussion revolves around the ideal gas law, specifically examining the relationship between pressure and temperature while keeping volume constant. The original poster attempts to find the rate of change of pressure with respect to temperature at a specified temperature, but expresses confusion regarding the constant involved in the equation.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the implications of the ideal gas law and question the necessity of certain information provided in the problem. There is uncertainty about the constant k and its role in the equation, as well as the expected behavior of pressure with temperature changes.

Discussion Status

The discussion is ongoing, with participants raising questions about the correctness of the problem setup and the interpretation of the constant k. Some guidance has been offered regarding the identity of k, but there is no consensus on how to proceed with the calculations or the implications of the provided answer.

Contextual Notes

There is a noted lack of information regarding the number of gas molecules, which may be relevant for understanding the constant k in the context of the ideal gas law. Additionally, the original poster is working under the assumption that the answer provided is accurate, despite the confusion it has caused.

cmajor47
Messages
53
Reaction score
0

Homework Statement


According to the ideal gas law, the pressure, temperature, and volume of a gas are related by PV=kT, where k is a constant. Find the rate of change of pressure (pounds per square inch) with respect to temperature when the temperature is 300[tex]^{o}[/tex]K if the volume is kept fixed at 100 cubic inches.


Homework Equations




The Attempt at a Solution


PV=kT
P=V-1kT
P=100-1kT
[tex]\frac{dP}{dT}[/tex]=100-1k

I don't know how to figure this out. We were given the answer, -.01 psi/[tex]^{o}[/tex]K but I don't know how to get to this with the k there.
 
Physics news on Phys.org
k is Boltzmann's constant.
 
This is weird. You're given information (T=300K) which is not necessary for calculating ∂P/∂T, and not given enough information to figure out what k is.

Moreover, pressure should increase as the gas is heated up. Yet "the answer" is a negative quantity!

Something is definitely not right here.
 
Tom Mattson said:
k is Boltzmann's constant.

That's what I thought when I first saw the problem. But where is the number of gas molecules in PV=kT? Either that equation was not written correctly, or k really is just "a constant".
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 35 ·
2
Replies
35
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 2 ·
Replies
2
Views
7K
Replies
14
Views
4K
  • · Replies 1 ·
Replies
1
Views
4K
Replies
1
Views
2K