The Mole

It's not a spy, a machine for digging tunnels, a burrowing animal, or a spot of skin pigmentation - it's - a unit of measurement containing about 6.02 x 1023 particles. The Chemical Mole

1 dozen atoms is 12 atoms!

1 pair of atoms is 2 atoms!

1 gross of atoms is 144 atoms!

1 mole of atoms is 602,214,199,000,000,000,000,000 atoms!

Avogadro’s Number (NA) 6.022 x 1023 particles / mole

Amadeo Avogadro 1776-1856

How BIG is 6.022 x 1023 ?

Could Bill Gates ever become a “moleonaire”?

How much interest would you get per second if 1 mole of $ was invested at an annual interest rate of 1% 6.02 x 1023$ x (1/100) = 6.02 x 1021$ (1 year) 6.02 x 1021$ / 365 days = 1.65 x 1019$ (1 day) 1.65 x 1019$ / 24 hours = 6.87 x 1017$ (1 hour) 6.87 x 1017$ / 60 min = 1.15 x 1016$ (1 min) 1.15 x 1016$ / 60 sec = 1.90 x 1014$ (1 sec) 190 TRILLIONS per SECOND !

Bill Gates only currently has 70 billion $ (70 x 109 $) 1 second of interest (at 1%) on a mole of $ is equivalent to 3000 times Bill’s Gates total wealth!

To become a moleonaire Bill Gates would have to earn 33,000 trillion $ a day for the next 50 years! Not likely!

Too bad Bill! Soooo sad…

The Pacific Ocean

How much water is there in the Pacific Ocean? Approximately 6 x 1020 L which is equivalent to 6 x 1023 mL ! The Pacific Ocean contains a mole of mL of water

A Galactic Analogy A mole of periods (.) lined up side by side would equal the radius of our galaxy (30,000 light years!)

A mole is big… real big. But is it really that important? Yes. Why?

Importance of the Mole Scientists use the mole to help count atoms, molecules, and compounds Example: 0.5 Moles of CO2 = 3.01x1023 Molecules of CO2 0.25 Moles of Carbon = 1.5x1023 atoms of Carbon How many molecules are there in 2.0 moles of O2? How many ATOMS are there in 2.0 moles of O2? 2.4 x 1024 Atoms of Oxygen

What is Avogadro’s Number? If I had a half-dozen eggs how many would I have? If I had a half-mole of eggs how many would I have? If I had a half-mole of copper atoms how many would I have?

Importance of the Mole Practice How many molecules are in 5.0 moles of NO2? How many atoms are there in 0.25 moles of Sulfur? How many molecules are there in 7.6 moles of C2O4? How many ATOMS are there in 7.6 moles of C2O4?

Importance of the Mole Moles tell us how many particles there are of something. Example: 1.0 moles of Sodium atoms = 6.02x1023 atoms of Sodium A mole is a big number… what do you suppose the mass of one mole of sodium atoms is? 23.0 grams! Golly-gee-whilickers! How did you find that out? Hmmm… !!!THE PERIODIC TABLE!!!

Moles of atoms Off the Periodic Table: 1 mole C = 12.011 g C 1 mole B = 10.81 g B 1 mole Cu = 63.55 g Cu 1 mole element = (atomic mass) g element • We can then say that …. Moles=grams / molar mass This is useful information! Watch!

Aluminum Can Lab How many moles of Aluminum (Al) are in an aluminum can? How many atoms of Aluminum (Al) are in an aluminum can?

Importance of the Mole Scientists can use the mole to determine how many particles are in a sample. Example: If you have 5 grams of water, how many water molecules do you have? 1st we need to determine the Molar Mass for Water

How do I find Molar Mass you Ask? Determine the formula for the molecule. EX. Water is Dihydrogen Monoxide H2O Find the molar mass for each atom in the molecule. H = 1.008 g/mole O = 15.994 g/mole

But Wait!! There are two hydrogen atoms in a molecule of water, so… 2H = (1.008 g/mole) X 2 = 2.016 g/mole H Now that I know the molar mass for the atoms in water, I can calculate the formula mass for water: 2.016 g/mole H + 15.994 g/mole O 18.01 g/mole H2O

In Summary: Mole Formulas (You need to know these!) Moles * Molar mass = Mass of Sample (I write it as Moles*MU = MG) Moles is how many moles you have Unit Mass is the mass of whatever unit you are dealing with (atoms, molecules, etc) Mass of Sample is the mass of your sample Moles =NP/NA NP = Number of particles (how many atoms, molecules, etc. your sample contains) NA=Avogadro’s Number Moles = grams/molar mass