評(píng)論
打印
I don't think you see anything happening to you
現(xiàn)在應(yīng)該還沒發(fā)生
I'm still working on it
我還在努力
I'm getting tired here
我有點(diǎn)累了
Something happening?
發(fā)生了什么嗎
Oh, my goodness, I could see myself
哦，我的天，我可以看到我自己了
Well, this is a real workout, I'll tell you
這個(gè)真的是太費(fèi)體力了
So what we've created here is a beautiful silver mirrored flask
這里我們做成了一個(gè)銀鏡燒瓶
So look at that
看這個(gè)
Dr. Dolhun has created a beautiful silver mirror
Dolhun博士做成了一個(gè)漂亮的銀鏡
It almost looks like a Christmas tree ornament
就像是圣誕樹上的裝飾品一樣
and a silver ornament could in fact be made this way
銀色裝飾確實(shí)也可以這樣做
So here's what's happening
這里情況是這樣的
Electrons from here, the glucose
電子來自葡萄糖
get transferred to the silver reducing it to silver 0
被轉(zhuǎn)移給銀離子，將其還原為Ag?
Silver 0 is insoluble in water. It's just silver metal Ag?
不溶于水，也就是銀金屬
And it's precipitating out on the inside of the flask
它會(huì)沉淀到燒瓶?jī)?nèi)面
forming the beautiful silver mirror that we see
形成我們所看到的漂亮銀鏡
Now this process is called reduction
這個(gè)過程叫作還原
And whenever something is reduced
有東西被還原
something else is oxidized
就有東西被氧化
So the glucose must be getting oxidized
被氧化的必然是葡萄糖
It becomes this
它變成這個(gè)
An oxygen was added here
一個(gè)氧被加到這里
Now this process is similar to metabolism in our bodies
這個(gè)過程很類似于我們體內(nèi)的代謝過程
We remove electrons from the sugar we eat
我們也會(huì)從吃下的糖中移除一個(gè)電子
and transfer them to the oxygen that we breathe
將其轉(zhuǎn)移給我們呼入的氧氣
In a reduction reaction like "mirror, mirror"
"魔鏡魔鏡"這樣的還原反應(yīng)
there might be energy released
會(huì)釋放出能量
In your body, this energy is harnessed in chemical bonds
人體內(nèi)，這些能量會(huì)用化學(xué)鍵儲(chǔ)存起來
stored for later
以便日后使用
The point of Tollens test was not to produce silver mirrors
Tollens測(cè)試的本身目的不是為了制造銀鏡
although a similar reaction is used for that today
雖然現(xiàn)在類似反應(yīng)確實(shí)被用作這個(gè)用途
The point was to distinguish between two types of sugars
其本身目的是為了區(qū)分兩種糖
One is containing aldehydes and one is containing ketones
一種中包含醛，一種中包含酮
Let me draw those
我畫一下這些
The difference is that in an aldehyde
差別在于，醛中
the carbon is connected to hydrogen
碳是同氫相連的
and in the ketone, the carbon is connected to another carbon
而酮同，碳是和另一個(gè)碳相連的
Aldehydes are more reactive than ketones
醛比酮的反應(yīng)性更強(qiáng)
so they will react with the silver ions
所以它們能同銀離子反應(yīng)
while the ketones will not
而酮?jiǎng)t不能
That's it for me. Hopefully, you enjoyed this video
就到這里吧，但愿大家喜歡這個(gè)視頻
And I will see you next time
我們下次再見
