In this video we'll prepare nitrous oxide gas via the oxidation of a

hydroxylamine salt. First of all measure out 25 grams of sodium nitrite. Note

that's nitrite not nitrate. Now measure out 40 mils of warm water. Add to the

sodium nitrite and then stir to form a solution. The warm water helps because as

the crystals dissolve they cause the solution to cool down.

Top the solution up with water so it's around 80 mils in total. Now measure out

25 grams of hydroxylaminium chloride otherwise known as hydroxylamine

hydrochloride. Again add around 40 to 50 mils of water and stir to dissolve. As

before the solution will cool down as the salt dissolves.

You can actually see condensation on the glass here. Now set up a fairly large

flask of 500 mils of above capacity equipped with a magnetic stir bar and a

ground glass joint. Add the sodium nitrite solution to the flask. Now set up

the apparatus with an addition funnel and a way to vent off the gas produced

into a tube.

If the addition funnel is a pressure equalized one then you'll need a tight

fitting stopper for it. Place the solution of hydroxylamine hydrochloride

into the addition funnel. Make sure the stopper is closed. To collect the gas

we'll use the one liter beaker filled with water and suspended upside down in

a large bowl of water.

We've used a magnetic stir bar to prop up one side of the beaker to allow a tube

to pass

through. Now set up the tube leading from the apparatus and ending directly under the

beaker of water. Because the first portion of gas given off will be air displaced out

of the apparatus. We'll start by leaving the tube outside the beaker however. So let's

start the reaction. Switch stirring on to moderate speed and slowly allow a small amount

of the solution into the flask.

You'll see bubbles appearing and the solution will start to heat up

considerably. As the temperature increases, addition of the hydroxylamine

solution results in almost immediate evolution of gas. After a couple of

minutes most of the air should be displaced out of the apparatus and you're

ready to begin collecting. Be careful not to add the solution too quickly because

the reaction can become very vigorous if you're not careful and discreet.

could cause a pressure buildup.

Gas collection can be pretty fast as you can see.

You'll need to hold or support the beaker in order to stop it tipping over once the

level of the liquid inside drops.

Once you stop adding the solution, it only takes a minute before the reaction dies down

and little more gas is generated.

Nitrous oxide is denser than air, and once we collected a full beaker we used a small

plate to cover it.

Let's see how a burning strip of paper reacts with the gas.

Not as vigorously as oxygen, but you can clearly see that the nitrous oxide is an oxidizing

agent and supports combustion pretty well.

.

Let's do a final experiment.

Here's some finely divided sodium nitrite and hydroxylamine hydrochloride.

Let's mix them together dry.

The reaction isn't as vigorous as a sodium nitrite with an ammonium salt.

It gives off a lot of heat and some nitrogen oxides in the smoke.

A good example of why mixing nitrite salts with anything containing an amine NH2 group

can be dangerous unless under controlled conditions.

The residue consists of sodium chloride.

Thanks for watching and stay tuned.

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