Warm-up 2/1 or 2/4

How many donuts are in 17.5 dozens?

How many cases would 200. cokes occupy? (1 case = 24 cokes)

Words that represent numbers

Pair = 2

Couple = 2

Dozen = 12

Baker’s dozen = 13

Gross = 144

Professions that have units

Baker: 1 dozen = 12 items

Paper manufacturer: 1 ream = 500 sheets

Farmer: 1 gross = 144 items

Coca Cola distributor: 1 case = 24 items

The Mole

The Chemist’s Unit

• Avogadro’s Constant, the Mole

• 1 mole (abbreviated mol)= 602,000,000,000,000,000,000,000 things

also written 6.02 x 1023 or 6.02 E 23

• Named after the scientist Amedeo Avogadro

It’s a big number…

Your paper clip chain of 1 mole of clips could circle the earth 400 trillion times!

A mole of aluminum cans is enough to cover the surface of the earth to a depth of over 200 miles!

If you connected paper clips at one million paper clips per second, it would take you 190 million centuries to finish stringing one mole of paper clips together!

It’s a big number…One mole of marbles would cover the entire Earth (oceans included) for a depth of three miles.

One mole of basketballs would fill a bag the size of the Earth.

One mole of pennies would cover the earth to a depth of 400 meters.

What would happen….

…If a mole of H2O molecules rushed into this room right now?

Would you be able to swim away?

Because particles are so small, a mole is a very convenient unit to use in chemistry!

Molar Mass

• Is the mass of a mole• For elements, one mole

equals the atomic mass in grams

• 1 mole C atoms = 12.011 g• 1 mole Cu atoms = ?

• 1 mole of H2O = ?

a.k.a•Molecular mass (MM) •Molecular weight (MW) •Formula mass (FM) •Formula weight (FW)•Gram formula mass (GFM) !!!!

What is the mass of one mole of H2O (Molar Mass)?

• Let’s break it down• 1 mol of H = 1.008 g• How many H are in the formula?

2 mol of H = 2 x 1.008 g = 2.016 g1 mol of O = 15.9994 g

mass of one mole of water = 18.015 g

Rephrased… Molar Mass H2O = 18.015 g/mol

Practice: calculate the molar mass

Na2SO4

Na2SO4

• Name it!!!• Calculate its

molar mass

• How many (particles) of sodium are needed to make one (particle) of sodium sulfate?

Na2SO4

• How many atoms of sodium are needed to make one formula unit of sodium sulfate?

• 2

Na2SO4

• How many dozens of of sodium atoms are needed to make one dozen formula units of sodium sulfate?

• 2

Na2SO4

• How many moles of sodium atoms are needed to make one mole of sodium sulfate?

• 2