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Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: highachiever on August 04, 2021, 07:33:26 AM

Title: Osmolarity
Post by: highachiever on August 04, 2021, 07:33:26 AM
hi!

does anyone know what the osmolarity (mosmol/l) of 100 mM (mmol/l) d-mannitol and 50 mM dimethyl sulfoxide is?
ive already figured that 150 mM of nacl is 300mosmol/l.

merci & best regards

- r
Title: Re: Osmolarity
Post by: Borek on August 04, 2021, 07:52:46 AM
If you have calculated osmolality for NaCl solution, can't you apply the same approach to the substances in question?
Title: Re: Osmolarity
Post by: highachiever on August 04, 2021, 08:04:07 AM
that's my problem.
wikipedia says cacl's osmorality is twice as high as its morality.
but then i came across another forum post that says that na2so4 osmorality is three times higher than morality because of its dissolution in water .
in addition, d-mannitol and dimethyl sulfoxide are much more complex ...
Title: Re: Osmolarity
Post by: Borek on August 04, 2021, 08:36:11 AM
wikipedia says cacl's osmorality is twice as high as its morality.

CaCl? No such compounds, If you mean CaCl2 it should be thrice. It depends on the dissociation and van 't Hoff factor.

Quote
in addition, d-mannitol and dimethyl sulfoxide are much more complex ...

Actually they are much simpler in the context.
Title: Re: Osmolarity
Post by: highachiever on August 04, 2021, 09:01:46 AM
oh no i'm sorry I meant nacl from my previous message.

yes, i know that osmorality mainly depends on the dissociation of the molecules (i didn't have the van't hoff factor in school ...), but i don't seem to find it online ... how exactly can i find out the osmorality of both molecules?
Title: Re: Osmolarity
Post by: Orcio_Dojek on August 04, 2021, 11:52:19 AM
Did you try using the google ?:

https://en.wikipedia.org/wiki/Van_%27t_Hoff_factor