Bromoform

Tribromomethane or bromoform is a toxic brominated hydrocarbon. It's analogous to chloroform but with the three chlorine atoms replaced with three bromines. Its not a very useful compound to have but its still interesting. I made some because I had recently obtained some sodium bromide and wanted to use it for something.

I chose to use the haloform reaction to make bromoform.

To make bromoform I started by adding 10g of sodium bromide and 150ml of water to a conical flask. I then poured in 205ml of 5% sodium hypochlorite bleach. The mixture was stirred, and I added 4ml of acetone with 10ml of water. I stirred the mixture well, then set it aside for 5 hours. After this, little drops of bromoform could been seen at the bottom of the flask. I shook the flask and the drops of bromoform came together into a homogeneous liquid. The little layer of bromoform at bottom was collected with a syringe. I determined I had 0.6ml of bromoform which is a 12.5% yield.

If you look carefully you can see the lower bromoform layer.

I attribute my terrible yield to a lot of the bromoform drops not collecting together as well as my clumsy collection of the product with the syringe.

NaBr + NaOCl ==> NaOBr

(CH3)2CO + 3 NaOBr + H2O ==> CHBr3 + CH3COOH + 3 NaOH