How Does Isothermal Expansion Affect Work Done and Temperature in an Ideal Gas?

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Homework Help Overview

The discussion revolves around the isothermal expansion of a monatomic ideal gas, specifically focusing on the temperature and work done during the process. The original poster presents a scenario involving 145 moles of gas expanding from 1.00 m³ to 4.00 m³ and seeks to determine the temperature at both the beginning and end of the process, as well as the work done by the gas.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants explore the relationship between pressure, volume, and temperature using the ideal gas law (PV=nRT). There are discussions about whether the temperature remains constant during isothermal expansion and how to calculate the work done using the formula W=nRTln(vf/vi). Some participants question the necessity of using the ideal gas law in this context.

Discussion Status

The discussion is active, with participants attempting calculations for temperature and work done. Some guidance has been offered regarding the use of pressure and volume in formulas, and there is an ongoing exploration of the implications of isothermal conditions on temperature.

Contextual Notes

Participants are working under the assumption that the process is isothermal, which implies constant temperature. There is a hint of confusion regarding the interpretation of temperature at the beginning and end of the process, as well as the application of the ideal gas law in this scenario.

fishingaddictr
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Suppose 145 moles of a monatomic ideal gas undergo an isothermal expansion from 1.00m^3 to 4.00m^3, as shown in figure. what is the temp at the beginning and end of this process? how much work is done by the gas during the expansion?

http://www.physics.brocku.ca/Courses/1p23/images/FG18_24.JPG

since it is isothermal the temperature is constant correct? :confused:
so to solve for the temperature would i just use pv=nrt with the respective values for pressure and volume?
and for the work done W=nrtln(vf/vi)

thanks
 
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You have p_i and p_f, and also v_i and v_f. Can you think of a formula that uses p and v ?

Hint: What are the units for pressure?
 
so i wouldn't use pv=nrt?
 
Try it out. Plug in the values of p_i and v_i into that formula.
Then plug in the values of p_f and v_f into that formula.
See what you get.
 
im getting .332 for the temperature.
 
and for the work i get 1670.42j
 
Now you tell me. Is temperature constant?
 
yup yup. thought it was tryin to trick me by askin the temp of beginnin and end like it was going to be two different values.
 

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