%Mole vs %Volume 2

[mielke]

Just to be sure...
When I see some natural gas mixtures mostly its broken down into volume percent but every once in a while i see mole percent. Its my understanding that these values (%mole and %volume) are the same. Am I correct?

 

[Chance17]

Yes, assuming you are not near the mixture critical point.

 

[ione]

I think the attached paper could help

 

[dcasto]

for a gas mixture, they can only report mole percent since the GC measures the molecules, not the volume.

You can download US standards for natural Gas compostional analysis from the gpagolbal.org website.

 

[shirishM]

Because your assumption here is Ideal gas conditions. PV=nRT so your V% should go along with the n% as long as your not close to the critical point or phase changes as previously point out.

So as a rule you can't apply this on liquid chromatograph readings. Adding Compressibility factors can help you get closer to those vol% to mol% conversions.

Awesome reference paper Ione; I will forward this to all everyone here.

S Mehta