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Hi, I'm Jessica
嗨，我是Jessica
and today I'm gonna be talking about a chemical demonstration
今天我要講的化學演示
I like to call the steaming gun
叫作蒸汽槍
So you've probably seen this before at the drugstore or in your house
你們在藥店或是家里可能見過這個
It's called hydrogen peroxide and it's the stuff you put on cuts
它叫過氧化氫，可以用于傷口消毒
but it has many other uses as well
它還有很多其它用途
from bleaching things, to powering rockets
包括漂白，為火箭提供動力等
depending on its concentration
具體用途取決于它的濃度
The solution that you get at the drugstore is usually 3%
藥店出售的溶液濃度通常是3%
So it's called hydrogen peroxide
這是過氧化氫
And its chemical formula is H202
其化學式是H2O2
So the atoms are arranged like this
原子是這樣排列的
It sort of looks like water
它和水有些像
but the extra oxygen makes the molecule more reactive
但多出來的氧原子讓分子反應活性更強
Now if you leave it alone, it decomposes into water and oxygen
把它放在那里，它會分解為水和氧氣
The equation looks like this
方程式是這樣的
I'm going to balance it
我來配平
And normally you can't see this reaction happening
通常你看不到這個反應發生
because at room temperature, it's very slow
因為室溫下，反應很慢
but there are many ways to speed it up
但為反應提速的方法有很多
like increasing the temperature or adding a catalyst
例如提高溫度，或加入催化劑
In this demonstration, MIT's Dr. John Dolhun uses
這個演示中 MIT的John Dolhun博士
catalyst to make the reaction go thousands of times faster than normal
將使用催化劑讓反應比正常情況快數千倍
Let's watch
我們看看吧
So we're gonna do this experiment here
這里我們將做這個實驗
and basically what we've got is we've got four bottles
這里我們有四個瓶子
we're each gonna do the experiment
我們兩人會做這個實驗
In the bottle, we've got out 15 mils of hydrogen peroxide here
瓶中，我們有15毫升過氧化氫
And we're going to be using a man-made catalyst
我們將使用一種人造催化劑
We're going to be using manganese dioxide
我們用到的是二氧化錳
We're each gonna take a scoop of this
我們兩個人都將取一勺這個
and we're going to put it in
放入到瓶子中
You can set it down on the tray
你可以把它放到盤子上來
and just, it's starting to work
它開始反應了
You won't have to stand up to see this
你們不需要站起來看
It's you can start to see some condensed water vapor
這里會開始有一些凝結的水蒸氣
forming inside the bottle
產生于瓶中
Oxygen bubbles are coming out
氧氣泡泡開始鼓出
Now we're just gonna lightly hold that
我們將輕輕地捏它
OK, so what happened?
這里發生了什么
