shaheerniazi - 25-11-2013 at 23:35
It is written on the internet that calcium hypochlorite reacts with acrtone to produce chloroform, what will happen if I use except calcium
hypochlorite, sodium hypochlorite?
woelen - 25-11-2013 at 23:40
With sodium hypochlorite you also get chloroform, but if you use plain 4% household bleach, then the solution will be very dilute and most of the
chloroform remains dissolved in the water of the bleach.
You need a distillation setup to get a decent yield. If you search sciencemadness (use google with your search terms such as "bleach chlororoform",
combined with the text site:*.sciencemadness.org) you will find a lot of information on this subject.
shaheerniazi - 26-11-2013 at 00:24
Thanks, but chloroform is not so soluble in water, only 0.8g/100ml of water at 20C?
woelen - 26-11-2013 at 00:57
Indeed, its solubility is quite low, but now so low that it does not dissolve at all. The reaction between bleach and acetone does give some
chloroform, which settles as a blob of liquid at the bottom, but it only is a small one.
If you want to see it, then take 100 ml of undiluted bleach and slowly, while stirring, add a few ml of acetone (not more, just a few ml). The liquid
will turn turbid and if you wait for some time, you will see a little blob of liquid. Some of the chloroform will be destroyed also while in solution.
Chloroform fairly easily hydrolyses to sodium formiate and sodium chloride in alkaline solution and in the presence of excess bleach, the formate is
easily oxidized further to carbonate ion. This side reaction leads to an additional loss. Especially the loss of bleach in the oxidation of formiate
leads to even more dilution. The colder your solution, the better the yield, hence the need of good stirring and slow addition of acetone. This avoids
strong local heating of the liquid.
shaheerniazi - 26-11-2013 at 01:16
So I should keep it in a ice bath for cooling and if even some sodium formiate forms and the turns into sodium carbonate, how can we seperate that?
woelen - 26-11-2013 at 01:32
Keep it cool. An ice bath is OK, but cold tap water is OK as well.
Isolating sodium formiate and sodium carbonate from these very dilute solutions with tons of other compounds in them is not useful. Sodium carbonate
can most likely be purchased in a supermarket as a cleaning compound.
Isolating chemicals from a brew of all kinds of other chemicals in general is not easy at all. This only is useful for valuable chemicals and usually
the isolation requires conversion to some separable form (e.g. make a precipitate, use large differences in solubilities). In this case I see no
direct and easy method which you can do at home for separating the carbonate and formiate from the solution.
shaheerniazi - 26-11-2013 at 01:39
Ok, and to seperate the water and chloroform can I use a syringe or can I boil all the water away?and if I leave the sodium carbonate is it soluble in
chloroform?
woelen - 26-11-2013 at 02:04
You need a glass pipette, not some plastic pice, because the plastic will be attacked by the chloroform.
If you boil, then chloroform boils off, not water, because chloroform has a much lower boiling point.
Sodium carbonate does not dissolve in chloroform, but that is not an issue anyway. Water does dissolve to some extent in chloroform and acetone also
does. The blob of liquid you extract from below the aqueous layer will be mostly chloroform, but it may contain a few percent of water and acetone.
But as a first start it would be nice if you get such a blob of liquid.
If you dispose of chloroform, do not pour it down the drain, it will attack the pipes if these are made of PVC or some other plastic material! Also
avoid inhaling the chloroform. Carefully smelling it, just to get to know its smell, can be done, but do not inhale the material for extended periods
of time or at high concentrations and do not smell it very often. If you want to get rid of it, pour it on a paper tissue outside and let it evaporate
and then throw the paper tissue in the household waste.
shaheerniazi - 26-11-2013 at 02:55
Ok, I just poured some acetone in sodium hypochlorite and there was just some bubbling and the a small layer of thick oil like clear substance made a
layer was that chloroform or acetone.
woelen - 26-11-2013 at 03:03
If the small oily layer is below the aqueous layer then that is (impure) chloroform. You can purify it somewhat by pipetting it from under the aqueous
layer and transferring it to another small bottle which has a small amount of water in it (approximately two times the volume of the chloroform will
do). By shaking, you extract acetone and other impurities in the chloroform into the water. In this way you at least get chloroform, which besides
water has not too much other impurities.
If you also want to get rid of the water you need a drying agent. A good drying agent is anhydrous MgSO4. For that, you again need to pipette the
chloroform to another dry vessel in which there is some anhydrous MgSO4. This compound then absorbs water while it does not dissolve in the
chloroform.
You'll learn something new from this experiment. Isolating and purifying a chemical leads to losses and these losses can become quite large,
especially if you only have a small quantity to be purified.
shaheerniazi - 26-11-2013 at 03:25
Awsome!!, but where will I get MgSO4 from?
Mr_Magnesium - 26-11-2013 at 04:06
MgSO4 is epsom salts
you can find that in your local pharmacy
woelen - 26-11-2013 at 04:31
If you buy epsom salt, then you buy the 7-hydrate, MgSO4.7H2O. You need the anhydrous salt. This can be made from the 7-hydrate by heating that in an
oven at 200 C or so. Look up the details over here or on internet, but making the anhydrous salt from the 7-hydrate should not be too difficult. You
can even recycle the salt. If it is used for drying, then you can reheat it again to make it anhydrous again. The only thing which limits the
recycling is that each time it is used, contaminants are absorbed as well, so recycling it too many times is not recommended, but recycling it once or
twice is a viable option.
[Edited on 26-11-13 by woelen]
shaheerniazi - 26-11-2013 at 05:04
Thanks, just went to the store with my father but couldnt find it.
Ill try some other day to find it.
BlackDragon2712 - 26-11-2013 at 11:03
http://www.youtube.com/watch?v=FugWTMD1GtE -> Using calcium hypochlorite
http://www.youtube.com/watch?v=XYbnNufX5-c -> Using bleach
shaheerniazi - 27-11-2013 at 03:45
Thank you BalckDragon2712 youre links are very helpful