Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: .1 M Water?
GreenD
National Hazard
****




Posts: 623
Registered: 30-3-2011
Member Is Offline

Mood: Not really high anymore

[*] posted on 23-4-2013 at 14:05
.1 M Water?


Bit confused.
Paper calls for a solution of reagents - (1eq and 1.2 eq - not that it matters) but then explains that this is in
"Water (.1M) and EtOH (.2M)"

? I've never seen anyone refer to the solvents, let alone water, in molarity.




ʃ Ψ*Ψ
Keepin' it real.
Check out my new collaborated site: MNMLimpact.com
View user's profile View All Posts By User
Pyro
International Hazard
*****




Posts: 1305
Registered: 6-4-2012
Location: Gent, Belgium
Member Is Offline

Mood: No Mood

[*] posted on 23-4-2013 at 14:46


could they mean 1,8g of water? or water in EtOH where 1l of the mixture contains 1,8g H2O?



all above information is intellectual property of Pyro. :D
View user's profile View All Posts By User
Prometheus23
Hazard to Self
**




Posts: 62
Registered: 6-6-2012
Member Is Offline

Mood: No Mood

[*] posted on 23-4-2013 at 19:38


It would be helpful if you could post some more details from the paper so we could see the full context.

But just taking a guess, could they have meant that the reagents being added were 0.1M in water and 0.2M in ethanol?
View user's profile View All Posts By User
GreenD
National Hazard
****




Posts: 623
Registered: 30-3-2011
Member Is Offline

Mood: Not really high anymore

[*] posted on 24-4-2013 at 19:57


Well the paper literally skims over this, as it is a "general procedure" and says
"Reagent A - 1eq and Reagent B - 1.2 eq were dissolved in water (.1M) and EtOH (.2M) and brought to reflux overnight."




ʃ Ψ*Ψ
Keepin' it real.
Check out my new collaborated site: MNMLimpact.com
View user's profile View All Posts By User
phlogiston
International Hazard
*****




Posts: 1379
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline

Mood: pyrophoric

[*] posted on 25-4-2013 at 03:09


I interpret this as follows:

1. Weigh 1.0 equivalents of reagent A and dissolve in as much water as needed to make a 0.1M solution
2. Weigh 1.2 equivalents of reagent B and dissolve into ethanol to make a 0.2M solution
3. reflux overnight.

I agree it could be more clear.
Also, it doesn't say whether the reagents are mixed and refluxed together, but I guess that should be clear from the context.




-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer
View user's profile View All Posts By User
Prometheus23
Hazard to Self
**




Posts: 62
Registered: 6-6-2012
Member Is Offline

Mood: No Mood

[*] posted on 25-4-2013 at 06:14


Yes exactly, that it what I meant phlogiston. They are giving the solvent and the concentration (essentially the volume of solvent to use) for each reactant.
View user's profile View All Posts By User
GreenD
National Hazard
****




Posts: 623
Registered: 30-3-2011
Member Is Offline

Mood: Not really high anymore

[*] posted on 6-5-2013 at 10:11


If only they would have thrown in "respectively"



ʃ Ψ*Ψ
Keepin' it real.
Check out my new collaborated site: MNMLimpact.com
View user's profile View All Posts By User
Prometheus23
Hazard to Self
**




Posts: 62
Registered: 6-6-2012
Member Is Offline

Mood: No Mood

[*] posted on 6-5-2013 at 10:45


Did you end up trying out the procedure the way phlogiston and I interpreted? Or were we off base a little?
View user's profile View All Posts By User
GreenD
National Hazard
****




Posts: 623
Registered: 30-3-2011
Member Is Offline

Mood: Not really high anymore

[*] posted on 6-5-2013 at 12:15


I am trying it your method today. Previously I just decided to throw in a 1:2 eq h2o:etoh, and the reaction didn't work.

But going off your interpretation, I used about 10x fold more solvent.

Its odd because, by your interpretation, and if they had thrown in the word "respectively" after, they would be asking for
.1M 4-cyano-methanebenzenebromide in water
and
.2M Sodium Sulfite in ethanol...

Which doesn't make sense, solubility wise, so I switched the two... Everything goes into solution at high temps, but these are not soluble at low temperatures.

We'll see... they request it run over night at reflux.




ʃ Ψ*Ψ
Keepin' it real.
Check out my new collaborated site: MNMLimpact.com
View user's profile View All Posts By User
Prometheus23
Hazard to Self
**




Posts: 62
Registered: 6-6-2012
Member Is Offline

Mood: No Mood

[*] posted on 6-5-2013 at 13:11


If you are still attempting to synthesize the compound you asked about in this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=22975#...

Then perhaps this procedure I came across could be of help to you.

http://www.organic-chemistry.org/abstracts/lit1/386.shtm

It essentially involves carrying out the reaction of your benzyl halide with excess sodium sulfinate in water under microwave irradiation (the latest fad it seems). I believe this could be carried out with sodium (bi)sulfite in place of a sulfinate to give the sulfonate you want.
View user's profile View All Posts By User

  Go To Top