Chemical Forums

Specialty Chemistry Forums => Other Sciences Question Forum => Topic started by: gunnersaurus on June 25, 2013, 02:21:12 PM

Title: mol%
Post by: gunnersaurus on June 25, 2013, 02:21:12 PM

hi,

i have a fluid composition which states 28.61% mol of h2s.

i also have a product which is rated for use in up to 2 % h2s

how to i get the two values above into the same units to check compatibility of this product in the fluid? ???

Thanks

Title: Re: mol%
Post by: billnotgatez on June 27, 2013, 11:38:24 PM

Do you mean H₂S
Is the fluid H₂O

Title: Re: mol%
Post by: gunnersaurus on June 28, 2013, 11:42:26 AM

Yes i mean H₂S

No the fluid is crude oil

Title: Re: mol%
Post by: Borek on June 28, 2013, 01:54:15 PM

Crude oil with 28.61% H₂S? Somehow this number doesn't look OK to me. I find it hard to believe H₂S has that high solubility, unless the mixture is kept under some pretty high pressure.

Title: Re: mol%
Post by: gunnersaurus on June 29, 2013, 10:20:24 AM

6500 psi...

anyway, back to the conversion..?

Title: Re: mol%
Post by: Borek on June 29, 2013, 10:34:05 AM

That's 440 atm, it no longer looks that impossible.

But I am not sure what the problem is - do you want to convert mole % to mass %?

Title: Re: mol%
Post by: gunnersaurus on June 30, 2013, 09:09:27 AM

yes i would like to convert it to % mass

Title: Re: mol%
Post by: curiouscat on June 30, 2013, 09:22:51 AM

Technically depends on the exact composition of the crude. You could assume something like MW=120?

The rest is then arithmetic.  The assumption is iffy though.

Title: Re: mol%
Post by: gunnersaurus on July 01, 2013, 07:56:52 AM

I have the composition but not the MW.

Can I simply multiply the % of each compound by the atomic mass of each compound, then add them together to get the overall MW for the fluid? :-\

Title: Re: mol%
Post by: curiouscat on July 01, 2013, 08:27:44 AM

Quote from: gunnersaurus on July 01, 2013, 07:56:52 AM

I have the composition but not the MW.

Can I simply multiply the % of each compound by the atomic mass of each compound, then add them together to get the overall MW for the fluid? :-\

You have composition as mol %? Or weight %?

Title: Re: mol%
Post by: gunnersaurus on July 01, 2013, 08:44:04 AM

mol%

Title: Re: mol%
Post by: curiouscat on July 01, 2013, 10:16:52 AM

Then your approach sounds right. Now MW not AW.

You don't even have to get the MW. Divide H2S's mass share by the sum of products of MW and mole. frac.