Today we're celebrating our 1000th Kimplaheer channel subscriber, and as a reward this video
here we've got some old foreign currency left over from an exotic vacation
sadly we will be unlikely to return to the beautiful country for a while
but the coins are made of cut pro nickel
which is seventy percent copper so we'll have to put them to a chemical use
let's first do a quick test
this is 68 percent concentrated nitric acid
and a coin
and a coin
yeah this works
the brown fumes are nitrogen dioxide with a boiling point of around 20
degrees
see it should be possible to prepare liquid nitrogen dioxide so we rigged up
a special apparatus we've got the 500 mil to neck flask and we've got the
large neck stopper and the small neck leading to an adapter the large neck
will fit our coins
the adapter then leads to a tube and condenser
and then we've got the receiving adapter and a small flask sitting in a bowl
we've also got a takeoff using an old nasty bit of plastic tubing and this
leads up to our extractor and means we hopefully won't die of nitrogen dioxide
poisoning use ventilation this stuff is very toxic and unpleasant we've got some
loose cotton and a coin inside the bottle this process is extremely difficult to achieve a
We'll open the adapter, and we've covered this with a few centimeters deep of anhydrous calcium chloride.
This will hopefully absorb moisture and stop any acid aerosol from getting into our product.
We've got the condenser hooked up to ice water for cooling.
And we've got the receiving flask in a bath of ice and water.
Okay, so that's our setup. Not too complex.
Here's our large-scale acid. 100 mils of 68% concentrated nitric acid.
Let's get this into the flask.
And now we're just waiting for the temperature to drop.
Okay, so, here we are in our ice bath to drop nicely and level out.
The reaction is exothermic, so we've got the reaction flask sitting in a bowl of water to moderate the temperature a bit.
Okay, let's get on with the show.
The reaction kicks off fast with lots of brown nitrogen dioxide gas coming off.
At the other br…
we've initially got a lot of brown gas escaping and being drawn away by the
extractor and we then start to see the gas escape die down and a dark colored
liquid is condensing into our receiving flask
the reaction in the flask is vigorous and produces quite a lot of heat the
liquid collection starts to slow down after a few minutes
it looks like our drying setup is working as well
and our ice baths are still nice and cold
distillation has stopped so we're going to add a couple more coins to the flask
again
as before we've initially got some brown gas
emitted and then we're going to add a couple more coins to the flask again
but then soon after we start receiving the liquid again this is rather
interesting and we'll come back to this later on nitrogen dioxide actually
exists in an equilibrium between the single nitrogen dioxide species and the
timer species which is known as di nitrogen tetroxide at lower temperatures
and the timer species which is colorless his favorite and you can see hearing our
apparatus as the gas passes through our image we can see that our brown gas is
into the chilled condenser it changes to a paler color.
We've also got a little of the liquid condensing at the top here.
You can see it's actually got a blue color to it.
The reaction with nitric acid also produces some nitrogen monoxide, or nitric oxide.
Although it's not supposed to happen except for at low temperatures, we seem to have some
of the nitric oxide reacting with the brown nitrogen dioxide to form dinitrogen trioxide,
which is then obviously soluble in the liquid nitrogen dioxide.
Although liquid nitrogen dioxide contains a lot of colorless dinitrogen tetroxide, when
pure it's still a dark brown color.
Dinitrogen trioxide however is blue.
You can see the blue color quite clearly in the receiving adapter.
We added two more coins, making six in total, and continued to collect the blue colored
distillate.
The temperature of the reaction has raised our water bath temperature a bit, but it's
under control.
No more distillate coming off now, so it looks like we're done.
We quenched the reaction by adding 100 mils of cold water.
This reduced the gas evolution down to virtually nothing.
We then prepared a solution of sodium carbonate in water, on adding some of this a little at
a time, and restoppering the flask.
We then added a little bit of sodium carbonate in water.
We were able to purge most of the browned gas out of the apparatus.
This is a little safer and easier to dismantle now!
Here's our product.
About six or seven mils of a dark blue liquid which we think is mostly nitrogen dioxide,
but with some dioxide present.
nitrogen trioxide dissolved in it it seems to be fairly stable when cold
and we didn't notice any pressure buildup in the flask with the white
background you can see the blue color a bit more clearly okay now let's do some
experiments first dripping some onto a glass dish at room temperature it
creates producing heavy brown nitrogen dioxide fumes
and soon disappears without a trace
here's some cool water
it doesn't stick around for long as it reacts with the water it heats up
causing it to boil off
as brown fumes again.
The resulting solution containing nitric and nitrous acids is strongly acidic as you can
see here.
If this forms inside your lungs, you are in whole worlds of trouble.
Now for something more exotic.
Here's some solid hypoxylamine hydrochloride.
It's a very vigorous reaction.
We decided not to add the solid to the liquid as it could well be explosive on a larger
scale.
Now some ethanol.
Very pretty miniature explosions.
The liquid remaining has a very strong aldehyde aroma.
That was pretty so let's do it again.
Next, here's some benzyl alcohol.
Not as vigorous as ethanol, but the liquid heats up and there's a very strong almond
aroma of benzaldehyde produced.
Not a very practical synthetic method though.
Finally, ice cold potassium hydroxide solution.
Very vigorous and it looks like most of the product escaped as gas.
Well that's all our experiments done and our product used up.
But it was a very interesting experiment.
We're intrigued by the way that the brown nitrogen.
Too much nitrogen.
Nitrogen dioxide gas comes off the reaction at first but doesn't condense.
Even when the condenser is already ice cold it takes about 10 to 15 seconds and then the
blue liquid is seen.
Maybe somehow it takes the generation of nitric oxide to get the product to actually condense.
Although nitric oxide has a much lower boiling point, perhaps it forms some sort of a seatrope
or abduct with nitrogen dioxide and dinitrogen dioxide which is what we end up with here.
We're interested to hear your ideas and theories.
Thanks for watching.