How Do You Calculate Final Pressure in a Compressed and Cooled Ideal Gas?

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SUMMARY

The final pressure of a compressed and cooled ideal gas can be calculated using the equation P1 V1 / T1 = P2 V2 / T2. Given the initial conditions P1 = 90.0 kPa, V1 = 0.0800 m³, T1 = 300 K, V2 = 0.0400 m³, and T2 = 260 K, the correct calculation yields P2 = 135.0 kPa. The initial attempt at solving this problem incorrectly used extraneous values and units, leading to an incorrect pressure result of 0.67 atm.

PREREQUISITES
  • Understanding of the Ideal Gas Law (PV=nRT)
  • Knowledge of gas laws and relationships between pressure, volume, and temperature
  • Ability to perform unit conversions (e.g., atm to kPa)
  • Familiarity with algebraic manipulation of equations
NEXT STEPS
  • Review the Ideal Gas Law and its applications in thermodynamics
  • Learn about unit conversions between different pressure units, specifically atm and kPa
  • Explore real-world applications of gas laws in engineering and physics
  • Practice solving problems involving multiple variables in gas law equations
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This discussion is beneficial for students studying thermodynamics, physics enthusiasts, and anyone involved in engineering fields that require an understanding of gas behavior under varying conditions.

dnl65078
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Homework Statement



A sample of an ideal gas is both compressed and cooled. The given variables for the gas are: P1 = 90.0 kPa, V1 = 0.0800 m3, V2 = 0.0400 m3, T1 = 300. K, T2 = 260. K. Calculate the final pressure.


Homework Equations



PV=nRT
P1 V1 /T1 = P2V2 / T2


The Attempt at a Solution



P2 = T1 V / P1V T2
= 299*1.29 / 1.40 *315 * 1.29
P2 = 0.67 atm

***I thought i was doing this right, but webassign says it's wrong... please advise?
 
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dnl65078 said:
P1 V1 /T1 = P2V2 / T2


The Attempt at a Solution



P2 = T1 V / P1V T2

this is wrong already. mulitply your first equation by T2 and then divide by V2.
299*1.29 / 1.40 *315 * 1.29
P2 = 0.67 atm
What are all those numbers that aren't in the problem statement?
I suppose the answer should be in kPa as well.
 

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