making chloroform attempt 1 (failure)
Used things:
- any solution of sodium hypochlorite (higher concentrations are better)
- acetone
- ice
bleach
I've bought a 1L 15% sodium hypochlorite solution.
This reaction needs space so i transferred it to 5L container.
1383 - 163.4 = 1219.6g of solution
1219.6 * 0.15 = 182.94g of hypochlorite
182.94 / (23+35.45+16) = 2.4572 moles of hypochlorite
acetone
Ideally this reaction takes 1 mole of acetone and 3 moles of hypochlorite producing 1 mole of chloroform, 2 moles of sodium hydroxide and 1 mole of sodium acetate.
3 NaOCl + (CH3)2CO → CHCl3 + 2 NaOH + CH3COONaAcetone forms azeotrope with chloroforms so 5% excess of hypochlorite should be used to react all of the acetone.
(2.4572 * 0.95) / 3 = 0.77811 moles of acetone should be used
0.77811 * (12*3+6+16) = 45.13038g of acetone
0.77811 * (12+1+35.45*3) = 92.867g of chloroform is the theoretical yield
preparations
Chloroform has solubility in water of 0.809g/100mL at 20C, to avoid needles loses higher concentrations of hypochlorite are recommended, although they need more cooling.
Hypochlorite solution was put into a freezer until it reaches the lowest temperature possible (even at -20C it shouldn't freeze because of high amount of sodium chloride dissolved in it). Also with it a bottle of water and ice cubes were put to freeze.
Haloform reaction is very exothermic and everything should be as cool as possible if not a runaway might start. If temperature of solution reaches 40C hypochlorite will start reacting with itself forming chlorate that won't be useful for this reaction. At temperatures above 60C chloroform produced will evaporate.
Keeping temperature as close to 0C as possible is important for good yield.
At higher concentrations of bleach, acetone should be added gradually as it really can runaway.
An ice bath was prepared and ice cubes were put into the solution.
reaction
Every 1 hours 1/3 of acetone was pipetted into solution to avoid overheating. Haloform reaction takes about 4 hours to fully complete, and a bit more time is needed for chloroform to settle at the bottom. Be aware that sodium hydroxide produced by this very reaction slowly reacts with chloroform
CHCl3 + 4 NaOH = HCOONa + 3 NaCl + 2 H2Oso water and chloroform should be separated without needless wait.
failure
The solution was so cold that a 1cm coating of ice appeared on container. For the whole reaction temperature was below zero and was rising slowly.
Only after the second addition of acetone the solution become cloudy but did not smell like chloroform.
After an hour after last addition solution was transferred into 4 400ml yogurt cups. Solution was crystal clear with no chloroform formation and strong scent of acetone.
And nothing changed after night.
After all of that i came to conclusion that my hypochlorite did not have too much of hypochlorite since it didn't have any scent and didn't increase temperature after addition of acetone. It's even said on label that it was produced in 2024 so it shouldn't be age problem (done at 2024). Well i've been scammed.