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