How big is a mole? (Not the animal, the other one.) - Daniel Dulek

Summary

The video script delves into the concept of the mole in chemistry, a unit for counting extremely small entities like atoms and molecules. It introduces the historical figure Avogadro, who proposed that equal volumes of gases at the same temperature and pressure contain an equal number of particles, a theory later proven correct. The mole, named after Avogadro's number (6.02 x 10^23), is used to quantify vast amounts of particles. The script uses analogies like donuts and basketballs to illustrate the immensity of a mole, comparing it to familiar units like dozens and pounds. It concludes by likening the mole to a practical unit of measurement in chemistry, akin to buying groceries by weight.

Takeaways

• 🧪 The mole in chemistry is a unit used to measure the quantity of atoms, molecules, or other particles.
• 🕵️‍♂️ Lorenzo Romano Amedeo Carlo Avogadro proposed that equal volumes of gases, at the same temperature and pressure, contain an equal number of particles.
• 🏗️ Avogadro's hypothesis was initially met with skepticism but was later proven correct, laying the foundation for atomic theory.
• 🔢 Avogadro's number, 6.02 x 10^23, represents the number of particles in a mole, a fundamental quantity in chemistry.
• 🌏 A mole of any substance contains a staggeringly large number of particles, such as 602 sextillion molecules in 18.01 grams of water.
• 🍩 A mole of donuts, if spread out, would cover the Earth to a depth of about five miles, illustrating the vast scale of a mole.
• 🏀 A mole of basketballs would be enough to create a new planet the size of Earth, further emphasizing the enormity of a mole.
• 💰 If you received a mole of pennies and spent a million dollars per second until you were 100 years old, you would still have 99.99% of the pennies left.
• 🛒 Chemists use moles to quantify substances in a way that is analogous to how we use units like pounds, dozens, or reams in everyday life.
• 🛒 The mole is a practical unit for chemists to work with extremely large numbers of particles, making calculations and measurements more manageable.

Q & A

What is the primary use of the term 'mole' in chemistry?

In chemistry, the term 'mole' is used to count a very large number of molecules, atoms, or other entities, specifically 6.02 times 10 to the 23rd, which is known as Avogadro's number.

Who was Lorenzo Romano Amedeo Carlo Avogadro and why is he significant in chemistry?

Lorenzo Romano Amedeo Carlo Avogadro was an Italian scientist who proposed that equal volumes of gases, at the same temperature and pressure, contain an equal number of particles. His hypothesis laid the foundation for the atomic theory and the concept of the mole in chemistry.

What was the initial reception of Avogadro's hypothesis about atoms and molecules?

Avogadro's hypothesis was initially not accepted by most scientists, as there was no clear difference between atoms and molecules, and his work was considered purely hypothetical.

How did Avogadro's hypothesis eventually get proven correct?

By the late 1860s, Avogadro's hypothesis was proven correct, although he had passed away in 1856. His work helped establish the atomic theory.

What is Avogadro's number and how is it used in chemistry?

Avogadro's number is 6.02 times 10 to the 23rd, representing the number of particles in one mole of a substance. It is used to express the quantity of atoms, molecules, or other entities in a substance.

How many gas particles are in a balloon at zero degrees Celsius and one atmosphere of pressure?

There are precisely 602 sextillion gas particles in a balloon at zero degrees Celsius and one atmosphere of pressure.

What is the significance of the number 602 sextillion in the context of the mole?

The number 602 sextillion represents Avogadro's number, which is the number of particles in one mole of a substance, making it a fundamental quantity in chemistry.

How many molecules of water are in 18.01 grams of water?

There are 602 sextillion molecules of water in 18.01 grams, which is equivalent to one mole of water.

What is a mole in the context of everyday quantities, and how does it compare to familiar units like a dozen or a gross?

A mole is a unit of measurement used in chemistry to represent a very large number of particles, specifically 6.02 times 10 to the 23rd. It is similar to familiar units like a dozen (12 items) or a gross (144 items), but on a much larger scale.

How can the concept of a mole be visualized in terms of everyday objects like donuts or basketballs?

If you had a mole of donuts, they would cover the entire earth to a depth of about five miles. If you had a mole of basketballs, you could create a new planet the size of the earth.

What analogy is used in the script to explain the practical use of moles in chemistry?

The script uses the analogy of buying items by the pound at a grocery store to explain the practical use of moles in chemistry, where chemists use moles to measure large quantities of atoms or molecules.

Outlines

00:00

🔬 Introduction to the Mole Concept in Chemistry

The script introduces the concept of the mole in chemistry, which is a unit used to measure a large number of atoms, molecules, or other particles. It clarifies that a mole is not a small animal or a skin growth but a scientific term. The mole is used to count extremely small entities, such as atoms, and it is named after Avogadro's number, which is approximately 6.02 x 10^23 particles. The script explains the historical context of the mole, mentioning the Italian scientist Lorenzo Romano Amedeo Carlo Avogadro who proposed that equal volumes of gases, at the same temperature and pressure, contain an equal number of particles. Despite initial skepticism, Avogadro's hypothesis was later proven correct and became foundational for atomic theory. The script uses analogies, such as a balloon of gas or a glass of water, to illustrate the vastness of a mole's quantity, emphasizing the difficulty in visualizing such large numbers.

Keywords

💡Mole (chemistry)

In chemistry, a 'mole' is a unit that represents the amount of a substance, specifically 6.02 x 10^23 particles, which is known as Avogadro's number. This concept is crucial for understanding the scale at which chemical reactions occur. The video uses the mole to illustrate the vast number of particles in everyday substances, such as the 602 sextillion molecules in 18.01 milliliters of water, which is equivalent to one mole.

💡Avogadro's number

Avogadro's number, 6.02 x 10^23, is the number of particles (atoms, molecules, etc.) in one mole of a substance. Named after the scientist Lorenzo Avogadro, it is a fundamental constant in chemistry that helps to quantify the relationships between different quantities in chemical reactions. The video emphasizes the enormity of this number to convey the sheer number of particles involved in chemical processes.

💡Lorenzo Avogadro

Lorenzo Romano Amedeo Carlo Avogadro was an Italian scientist who introduced the concept that equal volumes of gases, at the same temperature and pressure, contain an equal number of particles. His hypothesis, which was initially met with skepticism, laid the groundwork for atomic theory and is now fundamental to chemistry. The video highlights his contribution by explaining how his name is associated with the number of particles in a mole.

💡Atoms

Atoms are the basic units of matter, consisting of protons, neutrons, and electrons. They are the building blocks of all chemical substances. The video discusses atoms in the context of counting and measuring them, emphasizing their small size and how the concept of the mole allows chemists to work with quantities of atoms that are too large to count individually.

💡Molecules

Molecules are groups of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction. The video uses the example of water molecules to illustrate how a mole of any substance contains a vast number of these units, helping to explain the concept of a mole in a relatable way.

💡Gas particles

Gas particles refer to the individual molecules or atoms in a gaseous state. The video uses the example of gas particles in a balloon to demonstrate Avogadro's hypothesis that equal volumes of gases, at the same temperature and pressure, contain the same number of particles, which is a foundational concept in understanding the mole.

💡Chemical reactions

Chemical reactions involve the rearrangement of atoms to form new substances. The video indirectly touches on chemical reactions by discussing how the mole is used to quantify the reactants and products in such reactions. Understanding the mole is essential for predicting and measuring the outcomes of chemical processes.

💡Scientific notation

Scientific notation is a way of expressing very large or very small numbers, typically in the form of a number between 1 and 10 multiplied by a power of 10. The video uses scientific notation (6.02 x 10^23) to express Avogadro's number, making it easier to comprehend and work with such a large quantity.

💡Temperature and pressure

In the context of the video, temperature and pressure are physical properties that, when constant, ensure that equal volumes of gases contain an equal number of particles. This principle, known as Avogadro's law, is essential for understanding the mole and is a fundamental concept in chemistry.

💡Gas volume

Gas volume refers to the space occupied by a gas. The video explains that gases take up a lot of space due to the high kinetic energy of their particles. This concept is used to contrast the size of atoms with the space that gases occupy, helping to clarify misconceptions about the scale of atomic and molecular structures.

💡Molar quantity

A molar quantity is a measure of the amount of a substance that contains the same number of entities (atoms, molecules, etc.) as there are in 12 grams of carbon-12, which is Avogadro's number. The video introduces the term 'mole' as a practical way for chemists to refer to such quantities, making it easier to discuss and measure large numbers of particles.

Highlights

A mole is a concept in chemistry used to count molecules and atoms.

Lorenzo Romano Amedeo Carlo Avogadro proposed that equal volumes of gases, at the same temperature and pressure, contain an equal number of particles.

Avogadro's idea was initially not accepted by most scientists due to the lack of proof for atoms.

By the late 1860s, Avogadro's work was proven correct and laid the foundation for atomic theory.

Avogadro's number, 6.02 x 10^23, represents the number of particles in a mole.

A mole of any substance contains 602 sextillion particles.

Gas particles take up more space due to their high kinetic energy, which can be misleading about the size of atoms.

18.01 grams of water is equivalent to one mole of water molecules.

The concept of a mole helps chemists to quantify extremely small particles in a more manageable way.

Moles are difficult for students to visualize due to the vast number of particles they represent.

A mole of donuts would cover the entire Earth to a depth of about five miles.

A mole of basketballs could create a new planet the size of Earth.

If you received a mole of pennies at birth and spent a million dollars a second, you would still have most of your money at age 100.

Chemists use moles in the same way consumers use pounds or dozens for purchasing goods.

The mole is a standardized quantity in chemistry, similar to how a dozen is for eggs or a ream is for paper.

The mole is a fundamental concept that allows for the practical application of Avogadro's number in chemistry.

Transcripts

OK, today we're going to talk about the mole.

Now, I know what you're thinking: "I know what a mole is,

it's a small furry creature that digs holes in the ground and destroys gardens."

And some of you might be thinking that it's a growth on your aunt's face with hairs sticking out of it.

Well, in this case, a mole is a concept that we use in chemistry to count molecules,

atoms, just about anything extremely small.

Have you ever wondered how many atoms there are in the universe?

Or in your body? Or even in a grain of sand?

Scientists have wanted to answer that question,

but how do you count something as small as an atom?

Well, in 1811, someone had an idea that if you had equal volumes

of gases, at the same temperature and pressure,

they would contain an equal number of particles.

His name was Lorenzo Romano Amedeo Carlo Avogadro.

I wonder how long it took him to sign autographs.

Unfortunately for Avogadro, most scientists didn't accept the idea of the atom,

and there was no way to prove he was right.

There was no clear difference between atoms and molecules.

Most scientists looked at Avogadro's work as purely hypothetical,

and didn't give it much thought.

But it turned out he was right! By late 1860,

Avogadro was proven correct, and his work helped lay the foundation

for the atomic theory. Unfortunately, Avogadro died in 1856.

Now the thing is that the amount of particles in even small samples

is tremendous. For example,

If you have a balloon of any gas at zero degrees Celcius,

and at a pressure of one atmosphere, then you have precisely

six hundred and two sextillion gas particles.

That is, you have six with 23 zeros after it particles of gas in the container.

Or in scientific notation, 6.02 times 10 to the 23rd particles.

This example is a little misleading,

because gases take up a lot of space due to the high kinetic energy

of the gas particles, and it leaves you thinking atoms are bigger than they really are.

Instead, think of water molecules.

If you pour 18.01 grams of water into a glass,

which is 18.01 milliliters, which is like three and a half teaspoons of water,

you'll have 602 sextillion molecules of water.

Since Lorenzo Romano - uh, never mind - Avogadro was the first one to come up with this idea,

scientists named the number 6.02 times 10 to the 23rd after him.

It is simply known as Avogadros's number.

Now, back to the mole. Not that mole.

This mole. Yep, this number has a second name.

The mole. Chemists use the term mole

to refer to the quantities that are at the magnitude of 602 sextillion.

This is known as a molar quantity.

Atoms and molecules are so small, that chemists have bundled them into groups called moles.

Moles are hard for students to understand because they have a hard time

picturing the size of a mole,

or of 602 sextillion.

It's just too big to wrap our brains around.

Remember our 18.01 milliliters of water?

Well, that's a mole of water.

But how much is that?

Exactly what does 602 sextillion look like?

Maybe this'll help.

Exchange the water particles for donuts.

If you had a mole of donuts, they would cover the entire earth

to a depth of eight kilometers,

which is about five miles.

You really need a lot of coffee for that.

If you had a mole of basketballs, you could create a new planet

the size of the earth.

If you received a mole of pennies on the day you were born and spent a million dollars

a second until the day you died at the age of 100, you would still have more than 99.99%

of your money in the bank.

OK. Now we sort of have an idea how large the mole is.

So how do we use it?

You might be surprised to know that chemists use it the same way

you use pounds to buy grapes, deli meat, or eggs.

When you go to the grocery store, you don't go to the deli counter

and ask for 43 slices of salami, you buy your salami by the pound.

When you buy your eggs, you buy a dozen eggs.

When we hear the word dozen, we probably think of the number 12.

We also know that a pair is two,

a baker's dozen is 13,

a gross is 144, and a ream of paper is - anybody?

A ream is 500.

Well, a mole is really the same thing.

For a chemist, a mole conjures up the number 6.02 times 10 to the 23rd,

not a fuzzy little animal. The only difference is

that the other quantities are more familiar to us.

So there you have it - the story of the mole,

Avogadro, basketballs, and how to buy salami at the grocery store.