Mole to particle Calculations

Summary

This chemistry video script focuses on calculations involving moles, the SI unit for quantity of particles. It explains that one mole equals 6.02 x 10^23 representative particles, which can be atoms for elements, molecules for compounds, or formula units for ionic compounds. The script demonstrates how to calculate the number of particles in a given number of moles and vice versa, using the Avogadro's number. It also highlights the importance of using the 'ee' function on calculators for handling large exponents and maintaining significant figures in calculations.

Takeaways

• 🔬 A mole is a unit in chemistry that represents 6.02 x 10^23 representative particles.
• 🌐 The term for the smallest particle depends on the substance: atoms for elements, molecules for compounds, and formula units for ionic compounds.
• 🧭 The mole concept is used to calculate the quantity of atoms, molecules, or formula units in a given amount of substance.
• 📐 The script emphasizes the importance of using the 'ee' button on calculators for handling large numbers in calculations.
• 🔢 When calculating the number of representative particles in a substance, set up a proportion using the known value of Avogadro's number (6.02 x 10^23).
• ↔️ The script demonstrates both 'moles to particles' and 'particles to moles' calculations, showing they are essentially the same mathematical process.
• 🧮 For 'moles to particles', multiply the number of moles by Avogadro's number; for 'particles to moles', divide the number of particles by Avogadro's number.
• 💡 The 'ee' function on calculators simplifies calculations by directly inputting the power of 10, avoiding manual entry of '10^'.
• ⚖️ Units are crucial in these calculations, as they determine whether you are dealing with atoms, molecules, or formula units.
• 📚 The script is educational, aiming to teach chemistry students how to perform calculations involving moles and representative particles.

Q & A

What is the significance of the number 6.02 x 10^23 in chemistry?

The number 6.02 x 10^23 represents Avogadro's number, which is the number of representative particles in one mole of a substance.

What are representative particles?

Representative particles are the smallest units of a substance, such as atoms for elements, molecules for molecular compounds, and formula units for ionic compounds.

How are atoms, molecules, and formula units abbreviated in chemistry?

Atoms are abbreviated as 'atom', molecules as 'molec', and formula units as 'fu'.

What is the difference between molecular compounds and ionic compounds?

Molecular compounds consist of molecules, typically non-metals, while ionic compounds consist of formula units formed by the electrostatic attraction between cations and anions.

How do you calculate the number of atoms in a given number of moles of an element?

You set up a proportion with the number of moles given and Avogadro's number (6.02 x 10^23 atoms/mole), then cross multiply to find the number of atoms.

What is the purpose of the 'ee' button on a calculator in the context of chemistry calculations?

The 'ee' button is used to input large exponents more efficiently, such as Avogadro's number, by allowing you to input the base number followed by 'ee' and then the exponent.

How do you calculate the number of formula units in a given number of moles of an ionic compound?

The calculation is similar to that for atoms, using Avogadro's number (6.02 x 10^23 formula units/mole) and setting up a proportion.

What is the significance of significant figures in chemistry calculations?

Significant figures indicate the precision of a measurement or calculation. In the context of this script, the number of significant figures in the final answer should match the number in the given data.

How do you calculate the number of moles from a given number of atoms?

You divide the given number of atoms by Avogadro's number (6.02 x 10^23 atoms/mole), ensuring to use the correct function on the calculator to handle the large exponent.

Why is it important to use the correct function on the calculator when doing moles to particles or particles to moles calculations?

Using the correct function ensures accurate handling of large exponents and prevents calculation errors, which are common when dealing with Avogadro's number.

What is the abbreviation for 'mole' in most chemistry textbooks?

The abbreviation for 'mole' is 'mol'.

Outlines

00:00

🔬 Introduction to Moles and Particles

This paragraph introduces the concept of moles in chemistry, focusing on how it relates to the smallest particles. It explains that 1 mole is equivalent to 6.02 x 10^23 representative particles, which could be atoms, molecules, or formula units depending on the context. The video script clarifies that for pure elements, the smallest particle is an atom, for molecular compounds like water or carbon dioxide, it's a molecule, and for ionic compounds like sodium chloride, it's a formula unit. The script emphasizes the importance of understanding these distinctions for calculations involving moles. It also suggests using a calculator with an 'ee' function to handle large numbers efficiently, setting the stage for upcoming examples.

05:02

📚 Calculations with Moles

The second paragraph delves into the practical calculations involving moles. It demonstrates how to calculate the number of atoms in a given number of moles of an element, using potassium as an example. The script outlines the process of setting up a proportion, using the Avogadro's number (6.02 x 10^23) as a constant, and employing the 'ee' function on a calculator to simplify calculations with large exponents. The paragraph also covers calculating the number of formula units in ionic compounds like calcium chloride and molecules in molecular compounds like SO2. It stresses the importance of significant figures and the correct use of scientific notation in these calculations.

10:06

🧮 Converting Particles to Moles

The final paragraph in the script discusses the reverse calculation of determining the number of moles from a given number of particles. It uses the example of calculating moles of calcium from a specific number of atoms. The explanation includes setting up a proportion with the known number of particles per mole and solving for the unknown moles. The script highlights the importance of using the 'ee' function or parentheses with the power of 10 when dividing large numbers on a calculator to ensure accuracy. It concludes with a note on the importance of understanding the calculator's logic when performing these calculations to avoid common mistakes.

Keywords

💡Mole

A mole in chemistry is a unit that represents the amount of a substance, defined as 6.02 x 10^23 representative particles. This is a fundamental concept in the video, as it is used to convert between the macroscopic scale of grams and the microscopic scale of atoms, molecules, or formula units. The mole concept is central to understanding stoichiometry and chemical calculations, as it allows chemists to work with realistic amounts of substances rather than individual particles.

💡Representative Particles

Representative particles refer to the individual units that make up a mole. These can be atoms, molecules, or formula units, depending on the substance in question. The video emphasizes that the term 'representative particles' is a general way to refer to the smallest unit of a substance, which could be an atom for pure elements, a molecule for compounds like water or carbon dioxide, or a formula unit for ionic compounds like sodium chloride.

💡Atoms

Atoms are the basic units of chemical elements. In the context of the video, when discussing pure elements like iron, copper, or lead, the smallest unit considered is the atom. The mole concept is applied to atoms by stating that one mole of any element contains 6.02 x 10^23 atoms. This is used to calculate the number of atoms in a given number of moles of an element.

💡Molecular Compounds

Molecular compounds are compounds composed of molecules, which are groups of atoms bonded together, typically found among non-metal elements. In the video, examples like water (H2O) and carbon dioxide (CO2) are given. The video explains that for molecular compounds, the mole concept is applied at the molecular level, meaning one mole of a molecular compound contains 6.02 x 10^23 molecules.

💡Ionic Compounds

Ionic compounds are formed by the electrostatic attraction between positively and negatively charged ions. The video focuses on ionic compounds like sodium chloride (NaCl) and calcium phosphate (Ca3(PO4)2), emphasizing that the mole concept is applied at the formula unit level for these compounds. One mole of an ionic compound contains 6.02 x 10^23 formula units.

💡Formula Units

Formula units are the empirical units of ionic compounds, representing the simplest whole number ratio of ions in the compound. The video uses the term 'fu' as an abbreviation for formula units. For example, one mole of sodium chloride is equivalent to 6.02 x 10^23 formula units, which means it contains that many units of NaCl.

💡Calculations

The video provides detailed instructions on how to perform calculations involving moles, atoms, molecules, and formula units. It demonstrates how to convert moles to representative particles and vice versa, using proportions and the concept of significant figures. These calculations are essential for understanding chemical reactions and the quantities involved.

💡Significant Figures

Significant figures are the digits in a number that carry meaning contributing to its precision. The video stresses the importance of keeping track of significant figures during mole calculations to ensure the accuracy of results. For example, when calculating the number of atoms in 1.3 moles of potassium, the result is given with two significant figures.

💡Calculator Functions

The video introduces the use of calculator functions, specifically the 'ee' or '10^x' function, to handle large numbers in mole calculations. This function simplifies the process of multiplying by powers of ten, which is common when dealing with Avogadro's number (6.02 x 10^23). The video demonstrates how to use this function to calculate the number of representative particles in a given number of moles.

💡Conversion Factors

Conversion factors play a crucial role in mole calculations, as they allow chemists to convert between grams and moles, or moles and representative particles. The video uses the conversion factor of 6.02 x 10^23 particles per mole as a constant to perform various calculations, such as finding the number of atoms in a given number of moles of an element.

Highlights

1 mole is equal to 6.02 times 10 to the 23rd representative particles.

Pure elements are broken down to atoms.

Molecular compounds are broken down to molecules.

Ionic compounds are broken down to formula units.

A mole of any element equals 6.02 times 10 to the 23rd particles.

Calculations involving moles require a calculator with an 'ee' function.

Moles to representative particles conversion involves setting up a proportion.

The abbreviation for a mole is 'mol'.

To calculate the number of atoms in moles, multiply the number of moles by Avogadro's number.

Use the 'ee' button on the calculator for large numbers.

The 'ee' function simplifies calculations with powers of 10.

For formula units in moles of ionic compounds, use the same calculation method.

Molecular compounds are treated similarly to atoms in mole calculations.

The number of molecules in moles of a molecular compound is calculated by multiplying moles by Avogadro's number.

When converting from particles to moles, use division and the 'ee' function on the calculator.

Ensure to use significant figures correctly when reporting results.

Units are crucial in mole calculations to avoid confusion between atoms, molecules, and formula units.

Transcripts

so this video is going to look at

calculations with the mole associated

with the smallest thing which is

particles so mentioned this in the

previous video when we were talking

about the introduction of moles we're

going to call these representative

particles so 1 mole is equal to 6.02

times 10 to the 23rd

representative particles what exactly

does that mean

well it depends upon what it is is going

to be what its particle name

going to be so if it's just a pure

element we're going to call the smallest

thing

they're atom okay so if i have iron if i

have copper if i have lead

any of those elements all of the

elements off the periodic table we're

going to say the smallest thing that

we're breaking everything down to is

atoms if we have what we call molecular

compounds those are going to be those

non-metals on the right hand side we're

going to call them molecules

again for this intense purpose water is

considered a molecule

carbon dioxide is considered a molecule

again that distinction is not going to

be that critical for you right now

the difference between molecular

compounds and ionics but there is a

difference

ionic compounds is really where we're

going to focus most of our energy in

this course so sodium chloride

again calcium phosphate anything that

we've been

writing formulas for those are ionic

compounds and these are going to be

called

formula units so atoms are going to be

atoms molecules are going to be

abbreviated

m-o-l-e-c and you will see why in a

second

formula units uh chuckle chuckle is

going to be fu

so laugh all you want we're going to

call them fuse

so what does this mean in terms of the

calculation well that's what i'm going

to teach you here in a second but

realize that

a mole of any element is going to be

equal to 6.02 times 7

23. and in the previous videos

we did one mole is equal to so many

grams off the periodic table so

this is always going to be the same one

mole of calcium chloride is 6.02 times

123 formula units

mole of co2 6.02 times 123 molecules

a mole of anything is equal to 6.02

times on those 23 particles so

what you're going to see in these

problems is i'm going to use these three

words

um where they are um needed

but they all are going to do the same

calculation so the calculation is not

going to be much different

and for this calculation you do need to

you do want to have some kind of

calculator because i'm going to show you

a function on your calculator that's

going to be very helpful

for these calculations

so i am going to do what i call moles to

representative particles first and then

i'm going to go backwards from particles

to moles

so how many atoms are in 1.3 moles of

potassium

so again this is an atom because this is

just pure potassium

and you will see once we do a couple

examples here it does not matter

what it is for this calculation so we're

going to set up a proportion okay

and we know that one mole of anything is

going to be equal to 6.02 times 10 to

the 23

atoms okay or formula units or

molecules okay so i'll make this a

little bigger so you can see it a little

better sorry about that

so we're going to set up two proportions

okay the one on the left

is going to be my standard is always

going to be what's given in the problem

and what you're trying to find

and then over the right is going to be

how it's going to be the constant

essentially so how many atoms so i'm

going to put atoms on top but it doesn't

really matter

are in so many moles and we're going to

abbreviate a mole

as an mol and yeah you're going to say

really that's how much of an

abbreviation we drop the e

for mole but that is what you're going

to see in most chemistry textbooks is

mol

is the abbreviation for a mole so i want

to know how many atoms so that's my

x in 1.3 moles i'm going to write 1.3 on

the bottom

so what do i know about atoms well i

know 6.02

times 10 to the 23rd atoms is equal to

one mole

okay so we're going to cross multiply

okay and you're going to get the habit

of this

once you see a couple of these so x is

going to be equal to 6.02 times 10 of 23

times 1.3

well i want you to use a special button

on your calculator you need to find the

ee

button okay so find the ee button on

your calculator

okay it's going to be useful for this

very large number

okay and for this calculation it'll work

perfectly fine if you use like 10

carat to kind of get the power of 10 but

i want to show you a much simpler method

okay so you're going to type in 1.3

times 6.02 okay

then you're going to hit the senko

function key probably on your calculator

and you're going to hit the button that

says ee and e is going to appear

in the screen okay that's your power of

10.

so all i have to do is type in 23 so i

don't have to do times 10 to the carat

23.

this is far more efficient and you will

find in the next calculation we're about

to do

it's going to be important that you do

it this way so my answer is

7.8 and i have two sig figs here

times 10 to the 23rd so you will see in

the screen here it says

times 10 to the 23rd okay now for this

particular

exercise you will also see some

calculators just do

7.8 e23 um so that

is another way you might see a

calculator spit it out but e

in the language of the calculators means

power of 10.

all right so how many formulae units are

in 2.6 moles of calcium chloride

okay so calcium chloride is a formula

unit okay so i'm going to change the

vocabulary here

but one formula of units excuse me

uh 6.02 times 10 of the 23 formula units

is the same as one mole

so this calculation is same same okay

so pause the video and see if you can

come up with an answer for that

so again same setup x over the number of

moles given

is equal to 6.02 times seven of 23 over

a mole and you cross multiply

again in your calculator okay if i clear

out the calculator for this i'm going to

take 2.6

times 6.02 second function

e so that the e appears ahead again on

this calculator it is the blue key so i

hit that and then i hit 23 and then i

hit enter and it will spit out the

correct answer so 1.56

times 10 to the 24th again e24 might be

what your calculator shows you

so last but not least how many molecules

are in 5.6 moles of so2

so i'm going to pause this same kind of

idea

so again these are molecules because so2

is what we call a molecular compound

that's the only reason why

so again you cross multiply you should

get around 3.4 times 10 to the 24th and

you will see i cross this out because i

only have two digits here

so my answer could only have two digits

10 to the 24th very important

molecule so molecule is abbreviated

m-o-l-e-c

mole is abbreviated m-o-l okay and

that's where it gets very confusing very

quickly

so your units are going to be very

important when you're doing these types

of problems

so you might not have to worry about

that power of e

but when you do the backwards when you

do particles to moles

you have to use the proper function in

your calculator

so how many moles are there in 2.05

times 10 to the 23

atoms of calcium okay so again i'm going

to set it up this way it doesn't matter

how you set up these problems

what you put on top or what you put on

the bottom but just have to be

consistent

across both sides of the

proportion okay so

what is given in the problem is the

atoms i do not know the moles so that's

your

x now 6.02 times 723 atoms per 1 mole

so when you cross multiply okay

you have 6.02 times 10 to the 23

oops d3 x is equal to

2.05 times 10 to the 23rd

to get x by itself you have to divide

both sides by 6.02 times 10 to the 23rd

that's the only way you can

mathematically do that well

this is where you have to use that e

function or

if you're using 10 carat you're going to

have to use parentheses because you will

never i repeat you will never get the

correct answer

otherwise because the calculator does

not understand your logic with 10 carat

pretty easily

so type in 2.0 oops

2.05 second function e

23 hit division

okay 6.02 second function e

23. and then hit enter

okay and you should get a reasonable

number so this

is 0.341

moles okay because i have three digits

of significance here

this is power of 10 23 power of 10 23 so

you're really just dividing 2.05 by 6.02

okay so that number should be what it is

why don't you try this one on your own

and i will come back and show you the

answer

so 7.42 times 10 to the 24th you're

going to divide that by 6.02 times 10 to

the 23rd and you should get about 12.3

moles again with three significant

digits so you're always dividing into

that number so again

it's going to be 7.42 okay

second function e 24

divided by 6.02 second function e

23 and you will get 12.3 in your

calculator

if you use the 10 carat okay if you type

in 10

and do this carrot thing and do 23 or

something

the logic in the calculator does not

understand that as well

so that is why your numbers do not come

out correctly so please be aware of that

when you're doing these calculations