Chloroform Synthesis

In this experiment, the haloform reaction is employed to produce chloroform, or trichloromethane. Under controlled conditions, acetone and sodium hypochlorite are reacted together, separated from reaction byproducts, distilled, and separated yet again. Chloroform is famous for its classical use as a general anesthetic, though it is hardly used today due to its potential for acute toxicity. Chloroform, upon chronic exposure, is also a suspected carcinogen, affecting the liver especially.

As such, certain precautions must be taken- perform this reaction only outdoors or under a fumehood. Gloves and goggles must be worn at all times and a respirator should be on hand in case of emergency.

Reaction rate control is the key to a successful chloroform yield- the reaction between acetone and hypochlorite must be cooled to prevent a runaway reaction which leads to excessive evaporative loss of both product and reactant. The addition of acetone to the hypochlorite must be at a controlled rate.

The haloform reaction seen here is:
C3H6O (l) + 3*NaClO (aq) → CHCl3 (l) + 2*NaOH (aq) + NaC2H3O2 (aq)

Category:

Science & Technology

Tags:

• Chloroform
• CHCl3
• CCl3H
• haloform
• reaction
• chlorine
• acetone
• bleach
• sodium
• hypochlorite
• calcium
• distill
• vigreux
• column
• fractionating
• graham
• condenser
• aceton
• haloform-reaktion
• chemistry
• chemicals
• science

[UNITA4]

is there any way to determine when you've hit the chloroform layer during the seperation from the bleach/water/side-product/reac­tant mixture from the bucket while wearing a respirator, ie so I don't have to inhale it?

[ReactionFactory]

@UNITA4

The odor wasn't how we determined we were near the chloroform layer, it's just another sign. The main indication we used was that the biphase is clearly visible, and the chloroform shimmers under sunlight.

[Soccerownzu]

I am amazed by your setup. What is the cost of all of that equipment? I am a second year chem major and I have been looking into buying my own equipment.

[ReactionFactory]

@Soccerownzu

It's difficult to estimate how much money we've put into the hobby altogether, and what exactly would be required for this experiment, but it can add up. My advice regarding purchasing equipment is to buy parts which can potentially have multiple uses and are interchangeable, not some kit which can't have parts swapped out and upgraded. I buy much of my glassware from Kantu200 on eBay and recommend his store.

[wazzy198]

You should mention that chloroform breaks down into phosgene over time and when in contact with light, for example sunlight.

[ReactionFactory]

@wazzy198

That is true, with the added qualification that it is a slow process which requires light to occur at any appreciable rate and a supply of oxygen which is in contact with the chloroform.

[vvideoupl]

Very nice work, the only thing missing to purify your product is a little CaCl2 to dry it before storage.

[ReactionFactory]

@TheEmikodo

Worst ... idea ... ever.

[spotlightman1234]

there is almost nothing scarier than a runaway haloform reaction... *sees chloroform cloud* RUN!!!!

[ReactionFactory]

@andrewbjohman

Thanks! The addition took about 60 minutes for this volume of acetone.

[andrewbjohman]

Gr8 Vid...Cheers! Just a question regarding the length of time for the addition of the acetone. How long roughly, did it take to add the acetone?

[RealChemLabs]

Great job ReactionFactory! For another synthesis of chloroform check out our channel, Real Chem!