mole. The mole is an incredibly important term. But remember it's just a number. It's

摩爾。摩爾是一個極其重要的專門名詞。但是記住，它只是一個數字。它是

Avogadro's number. Why is it important? Well it allows us to deal with the massive number

阿伏伽德羅常數。爲什麽它是重要的？它使我們能夠處理數量龐大的

of atoms that are found in matter. This is one of my favorite demonstrations. You take

在物質裏的原子。這是我一個我喜歡的論證：你取

a five gallon jug. Put a little bit of alcohol in it, like ethanol. And when you light it

一個五加侖壺，放一點酒精在裡面，例如乙醇。而當你點燃它

you get this huge Whoosh, and this huge combustion of the ethanol. If we were to write out the

你會得到巨大的嗖的一聲，和巨大的乙醇燃燒。如果我要把它的化學式

formula, it looks like this. Why am I talking about this when I'm talking with moles? Well

寫出來，它看起來會像這樣。為什麼我在談論摩爾時會提到這個？

remember those coefficients that you write in front of the compounds in an equation like

還記得那些在分子式裏面，你寫在化合物前面的係數，譬如這些？

this represent the number of moles. In other words how many massive number of atoms are

代表著摩爾數。換句話說，是指有多少數量龐大的原子在

interacting. So it's really important when we deal with chemistry to understand what

相互作用。所以我們在學習化學時，了解摩爾是什麽

the mole is. And the mole is simply Avogadro's number. It's a number. It's 6.02 times 10

是非常重要的。而摩爾不過是阿伏伽德羅常數，一個數字。它是6.02乘10的

to the 23rd. Where does that number come from? It's derived from the number of atoms in 12

23次方。那個數字是從哪裏來的？它是從12克的碳-12的原子數目中

grams of carbon 12. But it just gives us a usable amount of material that we can work

衍生出來的。但它只是給了我們一個在實驗室中可以用的原料數量

with in the lab. So if we're ever looking at a reaction like this the coefficients remember

所以，如果我們在觀測一個這樣的化學反應，那些係數，記著，

are going to represent the moles. But it also serves as a bridge most importantly. A bridge

是在代表摩爾。它也在作為一座橋樑，最重要地。一座

between the mass of an object and the number of particles that are found within that object.

物體的質量，與粒子數目之間的橋樑。

And so where does the name come from? Avogadro was a Italian chemist. Worked many years ago

那麽，那個名稱是從哪裏來的？阿伏加德羅是一名意大利化學家。很多年以前

in the early 1800s. And so he came up with Avogadro's law. Basically as we increase the

在19世紀初時工作過。他提出了阿伏伽德羅定律。基本上，當我們增加

volume of a gas, he proposed that we were increasing directly the number of particles

氣體的體積時，他指出，我們在直接增加裏面的粒子數量，

that are found within that. It didn't matter what the gas was. Now he died before they

不論那是什麽氣體。他在其他人確實地提出並量化

actually came up and quantified this idea of the mole. But we still give him credit

這個關於摩爾的想法前去世了。但是，我們仍然將功勞歸於他，

for that early work. And so 1 mole is 6.02 x 10^23. But it's just a quantity. It's like

對於他的早期工作。如此，1摩爾等於6.02 × 10^23，但它只是一個數量。這就像是

if I have one egg we call that an egg. But if I have 12 eggs we call that a dozen. And

我們把一顆雞蛋叫作一顆雞蛋。但是有十二顆雞蛋時，我們稱之為一打。

so a mole is just a number. We could have a mole of anything. But it's most important

所以摩爾只是一個數字。我們可以有一個摩爾的任何東西。但它變得特別重要，

when we're dealing with chemicals. To give you an idea of how massive this number is,

當我們在處理化學物。為了讓您對這個數目的龐大有一個概念，

imagine if I had a mole of marbles. So just regular marbles like this. And I were to start

想像一下，如果我有1摩爾的彈珠，只是像這樣的平常彈珠，然後我開始

covering the earth. Well I could cover the earth in marbles and that covering of the

用它們覆蓋大地。我可以把地面用彈珠覆蓋，而大地的覆蓋層

earth would be 3 miles thick. And so there's a huge amount of numbers in Avogadro's number.

就有​​3英里厚。所以那裏有一個巨額數字在阿伏加德羅常數中。

And so when you're dealing with even small amounts of a compound, small amounts of an

所以當你在處理，即使是少量的化合物時，少量的元素

element, you have to understand that you have that many atoms that are found within there.

你要理解，你有這樣多的原子在裏面可以被發現。

Massive amounts. Again it forms a bridge. It forms a bridge between the mass of an object

大量的。再次，它形成了一座橋。它形成一座物體的質量

and the number of particles that are found there. And so it's really important at that

與粒子數量之間的橋樑。所以這是非常重要的，

kind of a bridge point. And so let's talk briefly about what an atomic mass unit is.

在那樣的匯合點。所以讓我來簡單談談什麼是原子質量單位。

And so let's say we take carbon dioxide for example. It's going to be found in the air.

比方説，以二氧化碳為例，它可以在空氣中被發現。

You breathe it out. It's atomic mass unit is going to be the mass of each of the individual

你將它呼出。它的原子質量單位將是每個個別的原子的質量。

atoms. And so we have 1 carbon. So we could look on the periodic table. And the atomic

那麽，我們有1個碳原子。我們可以查看週期表。它的原子質量

mass of that is 12.01. And then we're going to add 2 oxygens. Each of those are 16 on

是12.01。然後我們要加上2個氧原子。它們在

the periodic table. We could find it here. And so its atomic mass unit of carbon dioxide

週期表上都是16。我們可以在這裡找到它。所以二氧化碳的原子質量單位

is going to be 44.01. And so what is an atomic mass unit? It's the mass of one nucleon. So that

將是44.01。那麽，什麼是原子質量單位？它是一個核子的質量。

could be the mass of a proton or a neutron. Now why is that important? 1 mole of carbon

它可以是質子或中子的質量。為什麼它是重要的？ 1摩爾的

dioxide then is going to way 44.01 grams. Let's say we're looking at nitrous oxide. Could

二氧化碳重44.01克。比如，我們看看一氧化二氮。

you figure out the atomic mass unit of that? You could pause the video and try to figure

你可以弄清楚它的原子質量單位嗎？你可以暫停視頻，並嘗試計算。

this out. Well you'd have to find the nitrogen. You'd have to find the oxygen. And we'd simply

你要找到氮。你要找到氧。然後我們簡單地

add that up. So it would be 30.01. But if we had a mole of nitrous oxide that would

把它們加在一起。所以這是30.01。但是如果我們有1摩爾的一氧化二氮，那會

be 30.01 grams. And so it forms this bridge between the mass of an object and then the

是30.01克。所以這形成了這座物體的質量與

number of particles that are found within that. And this is where sometimes people get

内裏被發現的粒子的數目的橋樑。而這正是人們有時感到困惑，

confused about the mole when they're trying to make these mole conversions. And so let's

當他們在嘗試轉換摩爾單位。比方説，

say I had 9.01grams of water. It's almost 10 milliliters of water. And so that would

我有9.01克的水。這是差不多10毫升的水。所以那會

be about 2 teaspoonfuls of water. And let's say I wanted to figure out how many molecules

是大概2茶匙的水。又比方説，我想弄清楚有多少分子

of water are found inside there. Let me show you how the mole can act as a bridge. So we

在水裡面。讓我向你展示摩爾是怎樣連結作為一座橋樑的。那麽，我們

have 9.01 grams of water. The mole is going to act to convert that into the number of

有9.01克的水。摩爾會採取行動，將其轉換成粒子的數量。

particles. So first we use this mole conversion. Remember 1 mole of anything is going to be

所以首先我們作這個摩爾的轉換。記得，1摩爾的任何東西會是

the atomic mass of that in grams of water. So where am I getting the 18.02. I'm adding

它在單位克的水中的原子質量。那麽，我在哪裡得到18.02的數目？我在

the 1 oxygen, 16 plus the 2 hydrogens. And so one mole of water is going to be 18.02

將1個質量是16的氧原子，加上2個氫原子。所以1摩爾的水是18.02

grams. And so what I could do is I can cancel those grams. So now I've converted it to moles

克重。那麽，我可以做的是抵消這些克。現在我已經轉換了它到摩爾份

of water. Now we use Avogadro's number. And so I'm going to take 1 mole of water is equal

的水。現在我們使用阿伏伽德羅常數。現在1摩爾的水等於

to a number of molecules of water. So 1 mole is equal to Avogadro's number of that. I can

水分子的數目。所以1摩爾等於它的阿伏伽德羅數。現在我可以

now cross off my moles. And now I can solve for the number of molecules of water. And

劃掉摩爾。現在我可以得出水分子的數目。然後，

what I get, the math is easy here since I'm taking this, dividing by 18.02, we get 3.01x10^23.

我所得到的，算術在這裡是容易的，因爲我將它除以18.02，我們得到3.01 x 10^23。

And so I mean wrap your head around that for just a second. 2 teaspoonfuls of water,

然後，我要你用片刻去嘗試明白這個。 2茶匙的水，

the number of water molecules that are found in there would cover the earth in marbles,

這個數目的在裏面的水分子可以將大地用彈珠覆蓋，

if we converted those molecules to marbles 1.5 miles thick. And so now let me give you

如果我們將那些分子轉換成彈珠，厚1.5英里。那麽現在讓我給你

one for you. Let's say we have 5.72 grams of glucose, C6H12O6, could you convert that

一個例子。比方說，我們有5.72克的葡萄糖，分子式C6H12O6，你可以把它轉換

to molecules of glucose? And so here are the atomic masses here. I'll put the answer in

到葡萄糖的分子嗎？這裡有原子質量。我把答案放在

the video description down below so you can check and make sure you're doing it right.

下面的視頻說明，以便您可以檢查並確保把它做得正確。

Remember that mole serves that bridge. It's also incredibly important in chemical reactions.

記住，摩爾作爲那座橋樑。這在化學反應也是極其重要的。

This is one of my favorite reactions. This is a thermite reaction. We're getting a combination

這是我最喜歡的化學反應之一。這是一個鋁熱反應。我們得到一個

of iron oxide with aluminum. And so since it has the oxygen source inside it, this would

鐵氧化物與鋁的混合物。由於它裡面有氧源，它會

burn under water if you want it to. Okay. So what did we learn in summary? Could you

在水中燃燒，如果你想讓它。好的，那麼，總的來說，我們學習了什麽？您可以

pause the video and fill out what's in the blanks? Let me do that for you. So a mole

暫停視頻，並填補這些空格？讓我來幫你辦。如此，1摩爾

is Avogadro's number. Do you remember what that is? It's going to be 6.02 times 10 to

等於阿伏伽德羅常數。你還記得那是什麼嗎？這是6.02乘以10的

the 23rd. It's going to form a bridge between mass and the number of particles. And then

23次方。這將會形成質量和例子的數量之間的橋樑。然後

we use it to quantify chemical reactions. And so when we're looking at those coefficients

我們用它來量化化學反應。所以當我們看著那些係數

in the front of any kind of chemical reaction, it's going to tell us the number of moles.

在任何一種化學反應前面，它會告訴我們的摩爾的數目。

And so what should you have learned? Did you learn this? That the mole allows us to connect

那麽，什麽是你應該已經學習了的？你學到這個了嗎？摩爾讓我們連結

particles, moles, mass, volumes all together. Both qualitatively in the form of for example

粒子丶摩爾丶質量丶體積在一起。定性地和定量地，

a chemical reaction where we're writing that out. And quantitatively. Actually calculating

在一個我們寫出來的化學反應的形式上。和定量地。它實際上是在計算

the number of particles in material. So that's the mole. It's just a number. And I hope that

物質裏粒子的數量。所以這就是摩爾。它只是一個數字。我希望這

was helpful.

是有幫助的。