1. We use names to measure numbers: How many roses are in a dozen?
11.1: The Mole
Measuring Matter
We use names to measure numbers:
How many roses are in a dozen?
How many rolls are in baker’s dozen?
How many gloves are in a pair?
How many sheets of paper are in a ream?
How many objects are in a mole?

2. We use names to measure numbers: How many roses are in a dozen? 12
The Mole: Basic Concepts
Measuring Matter
We use names to measure numbers:
How many roses are in a dozen? 12
How many rolls are in baker’s dozen? 13
How many gloves are in a pair? 2
How many sheets of paper are in a ream? 500
How many objects are in a mole? 6.02x1023
The number that the unit represents is always constant

3. The mole (mol) is used to measure the amount of a substance.
The Mole: Basic Concepts
Measuring Matter
The mole (mol) is used to measure the amount of a substance.
1 mole = 6.02 x 1023 things
= molar mass
Avogadro’s number

4. So… how many apples are in a mole of apples?
The Mole: Basic Concepts
Avagadro’s number
So… how many apples are in a mole of apples?
6.02x1023 apples are in a mole of apples.
So… how many water molecules are in a mole?
6.02x1023 water molecules are in a mole.
6.02x1023 particles 1 mol

5. Just how much is a mole?
1 mol of pennies (6.02x1023 pennies) stacked on top of each other…
is 5.64x1017 miles high
Distance to the moon = 2.52x105 miles
Distance to Pluto = 2.75x109 miles
weighs 1.66x1018 tons
Weight of the earth = 6.6x1012 tons

6. That’s a lot! But…
1 mol of water molecules (6.02x1023 H2O molecules) is…
18.0 grams H2O (that’s .634 ounces)
18 mL H2O
Hmm… not a lot!
Atoms and molecules are so small that using Avagadro’s number makes numbers a lot easier to work with.