Is it possible to write pV=nRT as pV=mRT?

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    Pv=nrt
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Discussion Overview

The discussion revolves around the equation pV=nRT and its alternative form pV=mRT, particularly in the context of hydrology and gas laws. Participants are exploring the implications of using mass (m) instead of the number of moles (n) in the equation, as well as the relevance of specific gas constants.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant expresses confusion over their teacher's use of pV=mRT, suggesting it should be pV=mRT/M to account for molar mass.
  • Another participant proposes that pV=mRT is an alternative way of expressing the gas law when mass is known.
  • Some participants speculate that the teacher may be using a specific gas constant (R) for a particular gas, although one participant dismisses this approach as nonsensical, citing its use in climate sciences.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the appropriateness of using pV=mRT versus pV=nRT, with differing views on the validity of the teacher's approach and the implications of using specific gas constants.

Contextual Notes

There are unresolved assumptions regarding the definitions of R and the conditions under which each form of the equation is applicable. The discussion does not clarify the mathematical steps involved in transitioning between the two forms.

superjose
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Hi people. I've been scratching my head for some time now...

My teacher of hydrology class keeps posting pV = mRT and I don't know why he is doing that.

He's trying to get the density of the air.

But I know it should go like this

pV =mRT/M...

Can someone clarify this for me?

:s

Thanks.
 
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Probably he is using R that is specific for a given gas. Nonsense if you ask me, but I have seen it done in climate sciences.
 
jedishrfu said:
Apparently its an alternative way of writing the formula given the mass:

http://crown.panam.edu/thermodynamics/homework/javascript/gaslaw1f.htm

and here:

http://www.roymech.co.uk/Related/Thermos/Thermos_Specific_heat.html

Borek said:
Probably he is using R that is specific for a given gas. Nonsense if you ask me, but I have seen it done in climate sciences.

Thanks a lot, it has solved my doubts! :D
 
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