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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: beeman1 on April 02, 2008, 09:07:03 AM

Title: How do you convert Vapor pressure to ppm?
Post by: beeman1 on April 02, 2008, 09:07:03 AM

i have calculated the vapour pressure of some common odours diluted in mineal oil.  would now like t know how to calculate the ppm of the vapour that is being produced. Can i do this calculation without experimentation?

Amir

Title: Re: How do you convert Vapor pressure to ppm?
Post by: Valdorod on April 02, 2008, 01:23:56 PM

Amir:

concentration and pressure are related by the ideal gas equation:

P=(n/V)*RT

where (n/v) is the concentration in moles per liter.

or you can look at it in this form

P=MRT, where M is the molarity

If you know the density of your solutions then you can convert concentration into ppm.

Valdo

Title: Re: How do you convert Vapor pressure to ppm?
Post by: Borek on April 02, 2008, 01:28:49 PM

Which ppm? v/v? w/w?