Convert Mol/cm3 to PPMV: Pressure & Temp Considerations

[sneez]

I need to convert mol/cm3 into ppmv

how would i go about that if i know pressure and temperature ?

any leads ?

 

[dextercioby]

What's "ppmv"? I have a hunch it comes from "parts per million",bt what does "v" stand for ?

1 mol/cm^3 is the cgs unit for concentration.

Daniel.

 

[sneez]

parts per milion per volume , you just multiply ppm by 1.0e6

 

[pervect]

Are you using ppmv with gasses? A google shows that this appears to be the standard usage.

http://www.ch4.org.uk/glossary.php/Ppmv?term=p

has the usage info,

http://www.rotronic-usa.com/datasheets/Ref/Def/ppm_v.htm

has some sample calculations of how the term is used (with gasses).

If the term is being used for something other than gasses, the approach in the second url probably won't work - but I think it would be a bad idea to use the term for anything other than gasses.

 

[sneez]

I think i can work with that. Thanx a much

 

[dextercioby]

I hope u realize you can't make that conversion

dim (mol/cm^3)= S V^{-1}

dim (ppmv)=V^{-1}

Daniel.

 

[sneez]

yeah i had to convert everything into SI units.

ppmv=[(Gas rho) /(air rho) ] * 1.0e6

Gas rho = P/(kT) from P=nkT

thanx very much guys