this is the preparation of sodium potassium cyanide as a caution cyanide .

is a powerful and rapidly acting poison for which no antidote is available that .

you could stand a chance of administering yourself if anything goes .

wrong the preparation involves a reaction between potassium ferrocyanide .

and sodium metal it is performed in a rigid stainless steel container such as .

this one first of all measure out 40 grams exactly of anhydrous potassium .

ferrocyanide it is very important that the salt is completely anhydrous like .

this and not the crystalline dihydrate we also use sodium metal remove the .

sodium from its protective mineral oil dry it on a paper towel and weigh .

exactly 5 grams of metal chunks place a layer of potassium ferrocyanide on the .

bottom of the dry steel container .

cut the sodium metal into thin slices .

using a sharp knife place the slivers into the container and build layers of .

ferrocyanide and sodium metal ensuring that the metal is evenly distributed .

throughout the mixture finally pinching with a layer of ferrocyanide the .

reaction works well on a regular gas burner just make sure that there's no .

way for the container to tip over and spill start with a low heat in order to .

melt the sodium metal soon the mixture will start to turn brown and then a dark .

color at this point stir the mixture and keep stirring until it is a uniform dark .

color in about 15 minutes the mixture should liquefy use ventilation because .

the fumes given off could contain carbon monoxide which is toxic the liquid forms .

a white brittle solid .

pour the liquid out and allow to cool whilst cooling protect the solid with a .

sheet of foil just in case it shatters when cooled right down place into a .

beaker place 50 milliliters of hot water into the metal container and dissolve the .

contents as much as possible then pour this into the beaker containing the .

solid and gently stir in order to dissolve this should take from six to .

seventy mils of water and total when saturated the solution has a glossy .

sheen to it set up for vacuum filtration and carefully filter the mixture .

the black solid of paint is mostly iron which you can test with a brush or a .

brush and then use a magnetic stir bar the filtrate is a saturated solution of .

our crude product many organic reactions require an aqueous solution of cyanide .

and so this is suitable for use directly although it has a short shelf life due .

to hydrolysis and should be used immediately it can also be used to .

prepare a solid product but note that there is a considerable loss of .

to do this the filtrate is poured into an excess quantity of ethanol although .

some of the product remains dissolved the dehydrating action causes a lot to .

come out of solution is a fine precipitate stir for 10 to 15 minutes in .

order to ensure maximum removal of water here's the solid produced .

set up again for filtration and filter the solid drying it thoroughly for 15 .

minutes on the filter with a pump running .

here's the final product after drying in an oven a mixture of dry sodium and .

potassium cyanide which should have a good shelf life if not exposed to air or .

water .

an important note on disposal to dispose of filled trade washings and paper towels .

make a little solution of sodium hypoglycerate bleach then carefully add .

to the bleach the mixture may warm up so take care .

leave this for a few hours to neutralize cyanide before flushing down the drain to .

test the filtrate we added a small amount to a .

warm copper sulfate solution you can see the copper to cyanide immediately .

decomposing to form extremely toxic cyanogen gas this was just for .

curiosity and not something you should repeat here's the reaction I can't call .

cyanides fun but they are incredibly important and useful in organic .

synthesis to be treated with a deserving respect .