1. “The Mole” and Avogadro’s Number
6.022 x 1023

2. The Mole and Avagadro Avogadro's Mole Clip

3. Molecules and atoms are extremely small objects - both in size and mass. Consequently, working with them in the laboratory requires a large collection of them.
How large does this collection need to be?

4. A standard needs to be introduced. This standard is the "mole"
A standard needs to be introduced. This standard is the "mole". The mole is based upon the carbon-12 isotope.
Carbon 12 is the most frequently occurring isotope of the element Carbon (98%).

5. 1 mole = 6.022 x 1023 particles of any substance
Avogadro's Number!
We ask the following question: How many carbon-12 atoms are needed to have a mass of exactly 12 g? That number is NA - Avogadro's number.
Careful measurements yield a value for NA = x10^+23.
1 mole = x 1023 particles of any substance

6. Say What???
For example, if we stack 1 mole of pennies on top of one another, how tall would the stack be?
The answer is it would be so tall that the stack of pennies could reach the sun and back almost 500 million times!

7. Moles and Grams
The mass in grams of 1 mol of a substance is its “atomic mass”.
What is 1 mole of oxygen???
grams (its atomic mass)
What is 1 mole of calcium???
40.08 grams (its atomic mass)

8. Atomic Mass Unit (amu)
This is a unit that describes the mass of a single atom!
One single atom of Carbon has a mass of 12 atomic mass units. This is very small.
One mole of Carbon (6.022 x 1023 atoms of Carbon) weighs 12 grams. This is very large.

9. Copy these conversions.
1 mole = x 1023 atoms
1 mole = molecular weight (in grams)
=atomic weight from the periodic table
Abbreviation of Mole is mol

10. Determine the amount of iron present in 352 grams of Fe.

11. The Answer
352 grams Fe = mols Fe
55.85 grams
Atomic mass of FE

12. Practice Problems How many grams are in 2.50 mols of S? (x)
How many grams are in 3.20 mols of Cu?(x)
How many mols are present in 11 grams of Si?(/)
How many mols are present in 205 g of Hg?(/)
What is the mass in grams of 0.48 mol of Pt?(x)

13. Solutions!
80.2 g S
203 g Cu
0.39 mol Si
3.1 mol Hg
94 g Pt