When doing calculations, should pressure be in atm or Pa?

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Homework Help Overview

The discussion revolves around the appropriate units for pressure in calculations, specifically whether to use atmospheres (atm) or Pascals (Pa), with a focus on ensuring consistency in units for energy calculations expressed in joules.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the implications of using different units for pressure and emphasize the importance of consistent units across calculations. Some suggest that the choice of units may not matter as long as constants are adjusted accordingly.

Discussion Status

The discussion is active, with various participants offering insights on unit consistency and conversion practices. There is no explicit consensus, but several suggestions for maintaining clarity in calculations have been shared.

Contextual Notes

Participants note the importance of using consistent units, particularly mentioning the relationship between pressure, force, and area, as well as the specific gas constant used in calculations.

Lee
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When doing calculations, should pressure be in atm or Pa? (looking for answers in joules)
 
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Doesn't matter AFAIK as long as you adjust the constants for example R in PV=nRT.
 
Good'o. I just wanted to double check.
 
Use Pascals. P = F / A, Force is usually given in Newtons amd 1 Pa = 1 Nm^-2.

edit: should read the thread title, good practice anyway :).
 
Last edited:
all you need is to have is consistent units.
pressure in Pa, volume in cubic meters and R = 8.3145 J mol^-1 K^-1
then work will be in joules
 
Last edited:
Always choose the path with the least number of conversions.

Daniel.
 

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