Easy Temperature and Kinetic Throey Problem

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Homework Help Overview

The discussion revolves around a problem in thermodynamics involving the behavior of a gas under compression and temperature change. The original poster presents a scenario where a gas is compressed from an initial volume of 2.4 m³ to a final volume of 1.6 m³ while its temperature is raised to 30 degrees Celsius. The goal is to determine the final pressure of the gas.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to apply the ideal gas law, pV=nRT, but expresses uncertainty about their calculations and the appropriateness of the equations used. Other participants suggest using the relationship pV/T=constant, indicating a focus on the initial and final states of the gas. There is discussion about the variables involved and how they relate to the equations provided in the textbook.

Discussion Status

Participants are exploring different equations and relationships relevant to the problem. Some guidance has been offered regarding the use of the ideal gas law and the concept of constants in thermodynamic equations. There appears to be a productive exchange of ideas, with multiple interpretations of the problem being discussed.

Contextual Notes

The original poster mentions confusion regarding the values obtained for the number of moles and the application of the gas laws. There is an indication that the problem may involve assumptions about the initial conditions of the gas, such as standard temperature and pressure (STP).

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If 2.4m^3 of a gas initially at STP is compressed to 1.6m^3 and its temperature is raised to 30degreesC, what is the final pressure?

I thought this would be a easy one but my answers are coming out and don't look right.

I used pV=nRT

p=1.6m^3
V=2.4m^3
R=8.31J(mol*k) --- universal gas constant
T=30degreesC

So I plugged everything into the equation pV=nRT and solved for n and got .015403, it didnt look right so I converted 30degreesC to K (which equals 303.15K) then solved for n again and got .00154, which I am sure is also wrong.

Am I using the wrong equation?? There was only a few to choose from in the book:

pV/T=Constant, pV=nRT, pV/T=NKsubB

Please Help thanks
 
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if you look at what you are given you have Po, Vo, To. Then we know it is compressed and the temp raises so we know T and V after. We have to solve for P. from the equations below there's one that uses those 3 variables.
 
Im assuming pV/T=constant, because the other two deal with molecules.

so p(2.4m^3)/30=1.6m^3?
 
PV/T = constant (nK) and that works for both initial and final. Now you'll have two equations with two unknowns, Tfinal and constant

you also know initial pressure, initial volume, and initial temperature so you can find what the constant equals
 
Last edited:

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