Compression of monatomic ideal gas

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Homework Help Overview

The discussion revolves around the compression of a monatomic ideal gas and the subsequent temperature change, with a comparison to a diatomic gas. The original poster presents a scenario involving sudden compression and seeks to determine the resulting temperature after this process.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants explore the application of the ideal gas law and the First Law of Thermodynamics. There are attempts to relate specific heat capacities to the problem, and questions arise regarding the appropriate equations to use for sudden compression.

Discussion Status

The discussion is active, with participants providing hints and guidance on the relevant principles to apply. There is an acknowledgment of the need to consider adiabatic processes, and some participants express uncertainty about the correct approach and equations to use.

Contextual Notes

Participants note the constraints of the problem, including the sudden nature of the compression and the implications for heat transfer. There is also mention of specific heat capacities and their relevance under different conditions.

zygisyyy
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a monatomic ideal gas initially at 17°C is suddenly compressed to one-tenth its original volume. What is the tmeperature after copression? make the same calculations for a diatomic gas.
 
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Hi zygisyyy and welcome to PF. Please follow the rules of this forum and use the template when you seek help with homework. Show us the relevant equations and tell us what you tried and what you think about the problem. We just don't give answers away.
 
Hi, I thought maybe equation pV=nRT may work, but when i tried entering the values into the equation the answer was wrong ( near the proplem there are answers 1350 K for monatomic gas and 730 K for diatomic ). Then I tried surfing the web and found that the dimensionless specific heat capacity is 3/2 for monatomic gases and 5/2 for diatomic gases, but it said that it is so when the volume is constant. And I don't know what to do else.
 
This problem needs to be done using the First Law of Thermodynamics, not the ideal gas law. Hint: "Sudden compression" means that the gas is squeezed so fast that heat does not have a chance to enter or leave the gas. What does the First Law become in this case?
 
so i should use U=3/2*m/M*R*T?
or calculate as the sum of potential and kinetic energies? But i don't know the formula for the potential energy of monatomic and diatomic gases
 
What is an equation that expresses the First Law of Thermodynamics?
 
Q + A = delta U
 
OK, now the process in which no heat goes in and out of the system is an adiabatic process. for which pVγ = constant. Have you seen this equation?
 
thanks. now i know how to solve this equation
 

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