vmelkon
National Hazard
Posts: 669
Registered: 25-11-2011
Location: Canada
Member Is Offline
Mood: autoerotic asphyxiation
|
|
Making chloroform but bp is 49 °C
I have been making chloroform using Ca(OCl)2 and acetone. I first dissolve the Ca(OCl)2 in water and then add the acetone. I assume that the Ca(OCl)2
is 75% pure in my calculations. It obviously contains some Ca(OH)2.
The liquid (chloroform) I collected is obviously denser then water. I know because water floats on top of it.
I took the liquid (20 mL) and distilled it but there is something that distills at 49 °C. What is it?
CHCl3 bp = 61.2 °C
propanone bp = 56-57 °C
chloroacetone bp = 119 °C
|
|
|
DraconicAcid
International Hazard
Posts: 4334
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
Can you measure the density? Dichloromethane has a bp of 40 oC, but I'm not sure how you'd get that from this reaction.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
vmelkon
National Hazard
Posts: 669
Registered: 25-11-2011
Location: Canada
Member Is Offline
Mood: autoerotic asphyxiation
|
|
I could. I need a couple of days to make some more.
|
|
|
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
Posts: 1986
Registered: 2-3-2011
Member Is Offline
Mood: No Mood
|
|
It could be some condensation product between an aldehyde and alcohol.
Dimethoxymethane sublimes at 42 °C, for example.
|
|
|
vmelkon
National Hazard
Posts: 669
Registered: 25-11-2011
Location: Canada
Member Is Offline
Mood: autoerotic asphyxiation
|
|
I think it was because I was applying low heat so the vapors coming up were cooling as they rised.
I collected enough liquid and distilled "strongly" on its own. bp = 59 to 60 °C.
Density = 1.3984375 g/cm3 (3 digit approx = 1.40 g/cm3)
===================
CHCl3 bp = 61.2 °C
Density = 1.483 g/cm3
propanone bp = 56-57 °C
Density = 0.791 g/cm3
===================
So my chloroform has some acetone I guess.
|
|
|
Dariusrussell
Hazard to Self
Posts: 70
Registered: 27-6-2013
Location: Southie
Member Is Offline
Mood: Organometallics
|
|
Trichloromethane purification problems?
So I did the NaClO and Acetone route to producing trichloromethane. As it is distilling now, I have a significant amount of liquid (15mL plus) that is
boiling at 50C (My thermometer is pretty crappy so anywhere from 45 to 55)
It smells slightly sweet and has a bite like an alcohol (Like smelling methyl Salicylate)
I haven't smelled pure chloroform before and this boiling point is on the low side?
Is this my product? Or is it an impurity? It also doesn't look quite as refractive of pictures I have seen, but is still very refractive
|
|
|
Dariusrussell
Hazard to Self
Posts: 70
Registered: 27-6-2013
Location: Southie
Member Is Offline
Mood: Organometallics
|
|
Or actually if anyone has any easy tests (Other than smelling large quantities) for my product.
|
|
|
kristofvagyok
National Hazard
Posts: 659
Registered: 6-4-2012
Location: Europe
Member Is Offline
Mood: No Mood
|
|
Thermometer often lies, check its density. Take out 10 cm3 and weight it. If it is near to 14,8 g, than you got it.
But according to the sweet smell, and knowing that this reaction is pretty selective, you should have some chloroform.
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
"You can’t become a chemist and expect to live forever." |
|
|
Dariusrussell
Hazard to Self
Posts: 70
Registered: 27-6-2013
Location: Southie
Member Is Offline
Mood: Organometallics
|
|
Haha density, I should have thought of that.
I got 1.44g/mL which is definitely close enough, Stupid me.
In fact, I added some insulation around the top joint and the temp has already risen to 56 and rising.
Bfesser, you may close this thread
[Edited on 25-9-2013 by Dariusrussell]
|
|
|
Nicodem
|
Threads Merged
25-9-2013 at 12:44 |
Dariusrussell
Hazard to Self
Posts: 70
Registered: 27-6-2013
Location: Southie
Member Is Offline
Mood: Organometallics
|
|
Ok distillation done. I took a second density and ended up with 1.40 which is way low. This is most likely due to the fact that I messed up my
stoichiometry and added more 10g of acetone then there needed to be, knowing acetone and chloroform form an azeotrope (80%acetone 20% chloroform) that
boils at 64ish degrees, I theorize that I have a around 10g acetone in the mixture.
Here are some pictures of the (anti)purification:
I stored it in a UV blocking bottle, don't worry!
Would this acetone impurity render the solvent useless? Is there a way to extract it?
Thanks, Darius
|
|
|
papaya
National Hazard
Posts: 615
Registered: 4-4-2013
Member Is Offline
Mood: reactive
|
|
More acetone you say, then why not react the excess with more NaOCl NOW? I mean "wash" your chloroform with bleach.
|
|
|
macckone
Dispenser of practical lab wisdom
Posts: 2168
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline
Mood: Electrical
|
|
If you used insufficient hypochlorite, you probably have a lot of impurities. The ones I can think of are acetylaldehyde, dichloromethane, acetone,
chloroacetone (mono and di varieties) and smaller amounts of formic acid, acetic acid, formaldehyde, chloroacetic acid and possibly condensation
products. Since chloroform loves forming azeotropes, you probably have a good mix of stuff. The previous poster suggested adding more hypochlorite
which is probably the best solution.
|
|
|
vmelkon
National Hazard
Posts: 669
Registered: 25-11-2011
Location: Canada
Member Is Offline
Mood: autoerotic asphyxiation
|
|
Quote: Originally posted by macckone  | | If you used insufficient hypochlorite, you probably have a lot of impurities. The ones I can think of are acetylaldehyde, dichloromethane, acetone,
chloroacetone (mono and di varieties) and smaller amounts of formic acid, acetic acid, formaldehyde, chloroacetic acid and possibly condensation
products. Since chloroform loves forming azeotropes, you probably have a good mix of stuff. The previous poster suggested adding more hypochlorite
which is probably the best solution. |
I don't think you'll get some of those products that you listed like acetylaldehyde and dichloromethane, formic acid, acetic acid, formaldehyde.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
