Sciencemadness Discussion Board

My chloroform

vmelkon - 8-7-2014 at 13:05

This isn't a question. It's just an announcement.

I made some chloroform a second time and this time it is much better. I used slightly less propanone instead of trying to assume 75% stochiometric.
Density is 1.463 g/mL @ 25 C
compared to the old batch which was ~1.40 g/mL @20 or 25 C.

I also made more, about 400 mL. Feels like a dense liquid.

aga - 8-7-2014 at 13:23

Congratulations.

More detail regarding how the synthesis was improved may be useful to the audience.

Personally i have no use for it as yet, and the idea of storing 400ml of it scares the bejesus out of me in these sunny climes.

[Edited on 8-7-2014 by aga]

HgDinis25 - 8-7-2014 at 15:15

There are a few interesting things you could do with it, just in case you haven' thought of anything yet, like making some Chlorobutanol wich is a fairly interesting anesthetic.

Congratulations on your new chemical!

forgottenpassword - 9-7-2014 at 00:43

Quote: Originally posted by vmelkon  
This isn't a question. It's just an announcement.

I made some chloroform a second time and this time it is much better. I used slightly less propanone instead of trying to assume 75% stochiometric.
Density is 1.463 g/mL @ 25 C
compared to the old batch which was ~1.40 g/mL @20 or 25 C.

I also made more, about 400 mL. Feels like a dense liquid.
It's a pointless announcement unless you add more details of quantities, temperature, reaction time. Please do.

vmelkon - 9-7-2014 at 08:01

Sure, if you guys want. This is going to be long.
I was using Ca(OCl)2 (calcium hypochlorite), available at the pool section of your hardware store or Walmart from a company called HTH.

Since I was using an old source of Ca(OCl)2, and the barrel is marked 65%, I assumed it is 32.5%. I have tried to determine how much actual Ca(OCl)2 it contains but is a hassle.

I based my calculations on my 1 L RBF. I had to do over 30 runs. I strongly recommend getting yourself a gigantic steel can or something and doing this in a single run.

10.0 mL of propanone
= 7.91 g of propanone
= 0.1361899 mol of propanone

How many mL of CHCl3 does it produce if yield is 100%?
10.9629756649 mL of CHCl3

How many mols of Ca(OCl)2 is needed?
(based on 2 CH3COCH3 + 3 Ca(OCl)2 => 2 CHCl3 + (CH3COO)2Ca + 2 Ca(OH)2)
3/2 * 0.1361899 mol
== 0.2042848335 mol of Ca(OCl)2
= 29.2096260598 g of Ca(OCl)2

Assuming 32.5 % Ca(OCl)2
= 89.8757724916 g of Ca(OCl)2 is needed

Assuming a yield of 85%, more Ca(OCl)2 is needed
= 105.7362029312 g of Ca(OCl)2 is needed

How much water is needed? (mL)
= 503.505728244 mL

So, bottom line
10.0 mL of propanone
105.7 g of impure Ca(OCl)2
504 mL of water to dissolve your Ca(OCl)2.

Put the water and Ca(OCl)2 into your 1 L RBF.
It takes hours (8 h?) to dissolve the Ca(OCl)2.
Once all is dissolved (except for some Ca(OH)2, place it in a fridge for 1 hour. My fridge is at -18 °C.
I think if the temperare in the RBF drops to -10 °C, it is good.
Add the propanone.
The temperature rises to 30 °C in 30 min and then begins to drop off.
In 2 hours, you can distill off the chloroform.
Use very gentle heating.
The reaction produces a lot of Ca(OH)2. It is difficult to filter off. I prefer to distill.

THE BIGGEST problem was that the solution would foam and some Ca(OH)2 would come into the liebeg condensor. Man, what a pain. This didn't happen last time.
The video of my previous attempt is here https://www.youtube.com/watch?v=HtW1IfdTiB0
I didn't make a video this time.

I collected all the chloroform plus water and Ca(OH)2 junk into a bottle. I did over 30 runs. The bottle seemed to have about 400 mL plus Ca(OH)2 junk floating on top.
In the end, I distilled this stuff and had about 400 mL of chloroform plus a layer of water on top.
I froze the water and poored the chloroform into a new bottle.

Density is 1.463 g/mL @ 25 °C, which is close to wikipedia's 1.483 g/mL
My last project was at 1.40 g/mL

SirViking - 9-7-2014 at 08:06

What projects do you have planned with your newly distilled chloroform?

vmelkon - 9-7-2014 at 13:07

Quote: Originally posted by HgDinis25  
There are a few interesting things you could do with it, just in case you haven' thought of anything yet, like making some Chlorobutanol wich is a fairly interesting anesthetic.

Congratulations on your new chemical!


Making chlorobutanol from chloroform directly? How do you make carbon-carbon bonds?

vmelkon - 9-7-2014 at 13:09

Quote: Originally posted by SirViking  
What projects do you have planned with your newly distilled chloroform?


On planning on using some of it to make CCl4 just for the heck of it (Cl2 + CHCl3 + UV light).

I will likely use the rest as solvent in different cases.

aga - 9-7-2014 at 14:21

do you think that a vigreux column would have helped with the foaming problem ?

Loptr - 9-7-2014 at 16:25

Quote: Originally posted by aga  
do you think that a vigreux column would have helped with the foaming problem ?


I have yet to attempt this synth, but if foaming is an issue could a surfactant be used, such as cetyl alcohol, to lower the surface tension?

Zephyr - 9-7-2014 at 21:06

Quote: Originally posted by vmelkon  
Quote: Originally posted by HgDinis25  
There are a few interesting things you could do with it, just in case you haven' thought of anything yet, like making some Chlorobutanol wich is a fairly interesting anesthetic.

Congratulations on your new chemical!


Making chlorobutanol from chloroform directly? How do you make carbon-carbon bonds?


I am not sure that I understand your question, the reaction is very simple and is simply the reaction of chloroform and acetone, usually catalyzed by potassium hydroxide.
Another reaction I will be attempting in the future involving chloroform is the synthesis of Dichlorocarbene, a useful organic starting point.

Zyklon-A - 11-7-2014 at 08:21

Quote: Originally posted by vmelkon  


Since I was using an old source of Ca(OCl)2, and the barrel is marked 65%, I assumed it is 32.5%.


So you assumed half of it decomposed just because it's old?
BTW, do you know how it decomposes?
It seems thermodynamically favorable for it to do so as follows:
Ca(OCl)2 → CaCl2 + O2.

However, Ca(OCl)2 tends to smell slightly of chlorine when stored so perhaps this?:

Ca(OCl)2 → CaO + Cl2 + 1/2 O2.

Perhaps an equilibrium exists between the two reactions...

[Edited on 11-7-2014 by Zyklon-A]

woelen - 11-7-2014 at 10:45

Decomposition of Ca(OCl)2 is a little bit more complicated:

One reaction is production of oxygen. This is the main reaction: Ca(OCl)2 --> CaCl2 + O2

Besides this, there is another reaction, due to humidity in the air. A simplified representation is given by the equations below:

Ca(OCl)2 + H2O <---> Ca(OH)2 + 2HOCl

HOCl then decomposes to H2O, O2 and Cl2 and HCl. The latter reacts with further Ca(OCl)2 and Ca(OH)2. This reaction causes the smell of Cl2 from calcium hypochlorite.

So, the main reaction is production of oxygen, a small fraction is production of Cl2. Every year or so, appr. 1% of the hypochlorite decomposes in this way and bottles of powdered Ca(OCl)2 slowly become pressurized, due to the formation of the O2.

HgDinis25 - 11-7-2014 at 11:10

Quote: Originally posted by vmelkon  
Quote: Originally posted by HgDinis25  
There are a few interesting things you could do with it, just in case you haven' thought of anything yet, like making some Chlorobutanol wich is a fairly interesting anesthetic.

Congratulations on your new chemical!


Making chlorobutanol from chloroform directly? How do you make carbon-carbon bonds?


I don't think I understood your question. I was, indeed, talking about the reaction between Chloroform and Acetone using an alkali base catalyst. However the reaction is much more tricky than simply add the 3 in a beaker and filter, that's why it would be a good challenge for you to try and you would then have an interesting product.