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Discussion Overview

The discussion revolves around a homework problem involving the isothermal compression of dry steam from a pressure of 1 bar to 4 bar, with an initial volume of 0.5 m³. Participants explore the relevant equations and concepts needed to calculate the final volume after compression.

Discussion Character

  • Homework-related, Technical explanation, Exploratory

Main Points Raised

  • One participant notes that isothermal compression means the temperature remains constant.
  • Another participant suggests using the ideal gas law (PV=nRT) to model the situation, indicating that since the process is isothermal, certain variables remain constant before and after compression.
  • A participant proposes the equation V2 = (P1V1)/P2 for calculating the final volume after compression.
  • There is a question about whether to convert the pressure from bar to another unit for the calculation.
  • One participant raises the need for additional information, such as temperature or superheat, suggesting that if the temperature is at a saturation level, condensation may occur during the process.
  • A later reply confirms that no additional information was provided in the original problem statement.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the need for additional information and whether the ideal gas law is appropriate for this scenario. There is no consensus on the best approach to solve the problem, and multiple viewpoints on the applicability of the ideal gas law and the implications of the phase of the steam are present.

Contextual Notes

Participants note potential limitations in the problem, such as the lack of information on temperature and the possibility of condensation affecting the calculations.

naim
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Homework Statement


Dry steam is compressed isothermally from a pressure of 1 bar to 4 bar. if the initial volume is 0.5 m^3, calculate the volume of the steam after compression

Homework Equations



Dont know

The Attempt at a Solution

 
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naim said:
Dry steam is compressed isothermally …

it means with the temperature staying constant :wink:

(from the greek "iso-", meaning "same")
 
so how do i calculate it , does anyone know the equation of how to do it?
 
Since this is dry (completely vapor state) you could model with the ideal gas law

PV=nRT

since it is isothermal T is does not change, therefore: n,R, and T are all constant and the right side of the equation is the same before and after compression, so
P1V1=P2V2

V2 = (P1V1)/P2 , plug and chug
 
do i convert the 1 bar ? or do i just keep it as
v2=(1x0.5)/4 ?
 
naim said:

Homework Statement


Dry steam is compressed isothermally from a pressure of 1 bar to 4 bar. if the initial volume is 0.5 m^3, calculate the volume of the steam after compression


Homework Equations



Dont know

The Attempt at a Solution

Is there anymore information, e.g., the temperature, or the amount of superheat? Using the ideal gas law, or Boyle's law would be appropriate for an approximation. If the temperature is at a saturation level between 1 bar and 4 bar, then at the intermediate pressure, there would be some condensation (vapor to liquid transformation).
 
no that was all the information that was given
 

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