Name: 固体窒素を作る! (Making SOLID Nitrogen!)
Uploaded: 2021-01-14T10:25:47.000Z
Duration: 4 min 43 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

Boiling point is something that we normally think of as a stable property of a substance.

But it really depends on what the pressure is around the substance,

so, for example, water only boils at 100 degrees Celsius, if the pressure is 1 atmosphere.

So if you reduce the pressure, then those water molecules that are going quite quickly

can easily escape from the water if there's no pressure pushing down on them.

So you can get water to boil at room temperature.

The funny thing about boiling water at room temperature

is that it actually decreases the temperature of the water.

That's because all the fastest water molecules escape,

I know everyone's a big fan of liquid nitrogen, but I've never seen solid nitrogen.

So we used the same trick, pumping out the very fastest nitrogen molecules.

And eventually, that decreased the temperature enough that the nitrogen actually froze.

I'm putting a thermocouple in there so we can measure the temperature of our liquid nitrogen.

Okay, so the temperature of our liquid nitrogen is about minus 196 Celsius.

And now we're going to evacuate the chamber.

The temperature's dropping, minus 199, minus 200...

We're coming up on the triple point of nitrogen.

The ice is actually getting sucked up by the reduced pressure up here,

and there is a higher pressure underneath the ice because the vacuum pump hasn't had a chance to work there.

and we got the whole surface so cold that carbon dioxide actually condensed out of the atmosphere,

and we formed solid carbon dioxide, dry ice, on the surface of the water.

字幕リスト動画再生

固体窒素を作る! (Making SOLID Nitrogen!)

eventually

concept

trick

solid